From 0d8b2f045b01bd923286095db2a5489240921c2b Mon Sep 17 00:00:00 2001
From: Kez <kejprogramer0909@gmail.com>
Date: Sat, 13 Dec 2025 03:48:24 +0900
Subject: [PATCH 1/9] feat: Add DatePicker component and YearMonthPicker sample
 screen, updating navigation and refactoring existing date picker sample.

---
 .../kotlin/com/kez/picker/date/DatePicker.kt  | 192 ++++++++++++++++++
 .../com/kez/picker/date/DatePickerState.kt    | 103 ++++++++++
 .../kez/picker/date/DatePickerStateTest.kt    |  90 ++++++++
 .../kotlin/com/kez/picker/sample/App.kt       |   5 +
 .../kez/picker/sample/ui/navigation/Screen.kt |   1 +
 .../ui/screen/DatePickerSampleScreen.kt       | 163 ++++++++-------
 .../kez/picker/sample/ui/screen/HomeScreen.kt |  10 +-
 .../ui/screen/YearMonthPickerSampleScreen.kt  | 121 +++++++++++
 8 files changed, 601 insertions(+), 84 deletions(-)
 create mode 100644 datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
 create mode 100644 datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePickerState.kt
 create mode 100644 datetimepicker/src/commonTest/kotlin/com/kez/picker/date/DatePickerStateTest.kt
 create mode 100644 sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/YearMonthPickerSampleScreen.kt

diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
new file mode 100644
index 0000000..263912a
--- /dev/null
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
@@ -0,0 +1,192 @@
+package com.kez.picker.date
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.LocalContentColor
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.Shape
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import com.kez.picker.Picker
+import com.kez.picker.DatePickerState
+import com.kez.picker.rememberDatePickerState
+import com.kez.picker.util.MONTH_RANGE
+import com.kez.picker.util.YEAR_RANGE
+import com.kez.picker.util.currentDate
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.number
+
+/**
+ * A date picker component that allows selecting year, month, and day.
+ *
+ * @param modifier The modifier to be applied to the component.
+ * @param pickerModifier The modifier to be applied to each picker.
+ * @param state The state object to control the picker.
+ * @param startLocalDate The initial date to display (relevant for initial index calculation if needed, though state handles values).
+ * @param yearItems The list of year values to display.
+ * @param monthItems The list of month values to display.
+ * @param visibleItemsCount The number of items visible at once.
+ * @param itemPadding The padding around each item.
+ * @param textStyle The style of the text for unselected items.
+ * @param selectedTextStyle The style of the text for the selected item.
+ * @param dividerColor The color of the dividers.
+ * @param selectedItemBackgroundColor The background color of the selected item area.
+ * @param selectedItemBackgroundShape The shape of the selected item background.
+ * @param fadingEdgeGradient The gradient to use for fading edges.
+ * @param horizontalAlignment The horizontal alignment of items.
+ * @param verticalAlignment The vertical alignment of the text within items.
+ * @param dividerThickness The thickness of the dividers.
+ * @param dividerShape The shape of the dividers.
+ * @param spacingBetweenPickers The spacing between the pickers.
+ * @param isDividerVisible Whether the divider should be visible.
+ */
+@Composable
+fun DatePicker(
+    modifier: Modifier = Modifier,
+    pickerModifier: Modifier = Modifier,
+    state: DatePickerState = rememberDatePickerState(),
+    startLocalDate: LocalDate = currentDate,
+    yearItems: List<Int> = YEAR_RANGE,
+    monthItems: List<Int> = MONTH_RANGE,
+    visibleItemsCount: Int = 3,
+    itemPadding: PaddingValues = PaddingValues(8.dp),
+    textStyle: TextStyle = TextStyle(fontSize = 16.sp),
+    selectedTextStyle: TextStyle = TextStyle(fontSize = 24.sp),
+    dividerColor: Color = LocalContentColor.current,
+    selectedItemBackgroundColor: Color = Color.Transparent,
+    selectedItemBackgroundShape: Shape = RoundedCornerShape(12.dp),
+    fadingEdgeGradient: Brush = Brush.verticalGradient(
+        0f to Color.Transparent,
+        0.5f to Color.Black,
+        1f to Color.Transparent
+    ),
+    horizontalAlignment: Alignment.Horizontal = Alignment.CenterHorizontally,
+    verticalAlignment: Alignment.Vertical = Alignment.CenterVertically,
+    dividerThickness: Dp = 1.dp,
+    dividerShape: Shape = RoundedCornerShape(10.dp),
+    spacingBetweenPickers: Dp = 20.dp,
+    isDividerVisible: Boolean = true
+) {
+    // Validate state whenever year or month changes to ensure day is within range
+    LaunchedEffect(state.selectedYear, state.selectedMonth) {
+        state.validate()
+    }
+
+    Box(modifier = modifier) {
+        Column(
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.Center,
+            modifier = Modifier.fillMaxWidth()
+        ) {
+
+            // Calculate initial indices based on startLocalDate logic if strictly needed,
+            // but usually we rely on the state's initial value. 
+            // However, Picker component uses `startIndex`. 
+            // We should sync them with state's initial values or just find index of state's current value.
+            
+            // To ensure 1:1 mapping with Picker's internal state on first render:
+            val yearStartIndex = remember { yearItems.indexOf(state.selectedYear) }
+            val monthStartIndex = remember { monthItems.indexOf(state.selectedMonth) }
+            // Day items change dynamically, so we can't fully pre-calculate a static list and index 
+            // without being careful.
+            
+            // Dynamic day items based on maxDay
+            val maxDay = state.maxDay
+            val dayItems = (1..maxDay).toList()
+            // Ensure selected day index is valid for the current dayItems
+            val dayStartIndex = remember(dayItems) { 
+                val index = dayItems.indexOf(state.selectedDay)
+                if (index >= 0) index else 0
+            }
+
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                horizontalArrangement = Arrangement.Center,
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                // Year Picker
+                Picker(
+                    state = state.yearState,
+                    modifier = pickerModifier.weight(1.2f), // Give Year slightly more width
+                    items = yearItems,
+                    startIndex = yearStartIndex,
+                    visibleItemsCount = visibleItemsCount,
+                    textStyle = textStyle,
+                    selectedTextStyle = selectedTextStyle,
+                    dividerColor = dividerColor,
+                    selectedItemBackgroundColor = selectedItemBackgroundColor,
+                    selectedItemBackgroundShape = selectedItemBackgroundShape,
+                    itemPadding = itemPadding,
+                    fadingEdgeGradient = fadingEdgeGradient,
+                    horizontalAlignment = horizontalAlignment,
+                    itemTextAlignment = verticalAlignment,
+                    dividerThickness = dividerThickness,
+                    dividerShape = dividerShape,
+                    isDividerVisible = isDividerVisible,
+                )
+                
+                // Month Picker
+                Picker(
+                    state = state.monthState,
+                    items = monthItems,
+                    startIndex = monthStartIndex,
+                    visibleItemsCount = visibleItemsCount,
+                    modifier = pickerModifier.weight(0.8f),
+                    textStyle = textStyle,
+                    selectedTextStyle = selectedTextStyle,
+                    dividerColor = dividerColor,
+                    selectedItemBackgroundColor = selectedItemBackgroundColor,
+                    selectedItemBackgroundShape = selectedItemBackgroundShape,
+                    itemPadding = itemPadding,
+                    fadingEdgeGradient = fadingEdgeGradient,
+                    horizontalAlignment = horizontalAlignment,
+                    itemTextAlignment = verticalAlignment,
+                    dividerThickness = dividerThickness,
+                    dividerShape = dividerShape,
+                    isDividerVisible = isDividerVisible,
+                )
+
+                // Day Picker
+                Picker(
+                    state = state.dayState,
+                    items = dayItems,
+                    startIndex = dayStartIndex,
+                    visibleItemsCount = visibleItemsCount,
+                    modifier = pickerModifier.weight(0.8f),
+                    textStyle = textStyle,
+                    selectedTextStyle = selectedTextStyle,
+                    dividerColor = dividerColor,
+                    selectedItemBackgroundColor = selectedItemBackgroundColor,
+                    selectedItemBackgroundShape = selectedItemBackgroundShape,
+                    itemPadding = itemPadding,
+                    fadingEdgeGradient = fadingEdgeGradient,
+                    horizontalAlignment = horizontalAlignment,
+                    itemTextAlignment = verticalAlignment,
+                    dividerThickness = dividerThickness,
+                    dividerShape = dividerShape,
+                    isDividerVisible = isDividerVisible,
+                )
+            }
+        }
+    }
+}
+
+@Preview(name = "Default", group = "DatePicker", showBackground = true)
+@Composable
+fun DatePickerPreview() {
+    DatePicker()
+}
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePickerState.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePickerState.kt
new file mode 100644
index 0000000..0d935d9
--- /dev/null
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePickerState.kt
@@ -0,0 +1,103 @@
+package com.kez.picker
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.remember
+import com.kez.picker.util.currentDate
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.number
+
+/**
+ * Creates and remembers a [DatePickerState].
+ *
+ * @param initialYear The initial year to be selected. Defaults to the current year.
+ * @param initialMonth The initial month to be selected. Defaults to the current month.
+ * @param initialDay The initial day to be selected. Defaults to the current day.
+ * @return A [DatePickerState] initialized with the given date values.
+ */
+@Composable
+fun rememberDatePickerState(
+    initialYear: Int = currentDate.year,
+    initialMonth: Int = currentDate.month.number,
+    initialDay: Int = currentDate.day
+): DatePickerState {
+    return remember(initialYear, initialMonth, initialDay) {
+        DatePickerState(initialYear, initialMonth, initialDay)
+    }
+}
+
+/**
+ * State holder for the DatePicker.
+ *
+ * Manages the state of the year, month, and day pickers.
+ * Automatically adjusts the selected day if it exceeds the maximum valid day for the new year/month.
+ *
+ * @param initialYear The initial year to be selected.
+ * @param initialMonth The initial month to be selected.
+ * @param initialDay The initial day to be selected.
+ */
+@Stable
+class DatePickerState(
+    initialYear: Int,
+    initialMonth: Int,
+    initialDay: Int
+) {
+    val yearState = PickerState(initialYear)
+    val monthState = PickerState(initialMonth)
+    val dayState = PickerState(initialDay)
+
+    val selectedYear: Int
+        get() = yearState.selectedItem
+
+    val selectedMonth: Int
+        get() = monthState.selectedItem
+
+    val selectedDay: Int
+        get() = dayState.selectedItem
+
+    /**
+     * The currently valid maximum day for the selected year and month.
+     * Calculated dynamically based on the selected year and month.
+     */
+    val maxDay: Int
+        get() = daysInMonth(selectedYear, selectedMonth)
+
+    init {
+        // Ensure initial day is valid
+        if (initialDay > maxDay) {
+            dayState.selectedItem = maxDay
+        }
+    }
+    
+    // We need to observe changes to year/month to clamp the day
+    // However, PickerState updates are independent composable states.
+    // In strict Compose, we should probably use derivedStateOf or side-effects in the composable calling this.
+    // But since PickerState internal `selectedItem` is mutableStateOf, 
+    // we can try to hook into the validation in the UI layer or make this class reactive.
+    // For simplicity with existing PickerState pattern:
+    // The UI (DatePicker) should observe selectedYear/selectedMonth and update the day picker's range/value if needed.
+    // OR we expose a function to validation.
+    
+    // Actually, simply querying `maxDay` in the UI to limit the list of days is the best approach.
+    // But we also need to clamp the *selected* value if it goes out of range.
+    // Let's add a function to validate and adjust.
+    fun validate() {
+        val currentMax = maxDay
+        if (dayState.selectedItem > currentMax) {
+            dayState.selectedItem = currentMax
+        }
+    }
+    
+    private fun daysInMonth(year: Int, month: Int): Int {
+        return when (month) {
+            1, 3, 5, 7, 8, 10, 12 -> 31
+            4, 6, 9, 11 -> 30
+            2 -> if (isLeapYear(year)) 29 else 28
+            else -> 31 // Should not happen with 1-12 range
+        }
+    }
+
+    private fun isLeapYear(year: Int): Boolean {
+        return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)
+    }
+}
diff --git a/datetimepicker/src/commonTest/kotlin/com/kez/picker/date/DatePickerStateTest.kt b/datetimepicker/src/commonTest/kotlin/com/kez/picker/date/DatePickerStateTest.kt
new file mode 100644
index 0000000..ba112d5
--- /dev/null
+++ b/datetimepicker/src/commonTest/kotlin/com/kez/picker/date/DatePickerStateTest.kt
@@ -0,0 +1,90 @@
+package com.kez.picker.date
+
+import com.kez.picker.DatePickerState
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class DatePickerStateTest {
+
+    @Test
+    fun testMaxDay_January() {
+        // 2023-01-01
+        val state = DatePickerState(initialYear = 2023, initialMonth = 1, initialDay = 1)
+        assertEquals(31, state.maxDay)
+    }
+
+    @Test
+    fun testMaxDay_February_NonLeapYear() {
+        // 2023-02-01
+        val state = DatePickerState(initialYear = 2023, initialMonth = 2, initialDay = 1)
+        assertEquals(28, state.maxDay)
+    }
+
+    @Test
+    fun testMaxDay_February_LeapYear() {
+        // 2024-02-01 (Leap Year)
+        val state = DatePickerState(initialYear = 2024, initialMonth = 2, initialDay = 1)
+        assertEquals(29, state.maxDay)
+    }
+
+    @Test
+    fun testMaxDay_February_LeapYear_Century() {
+        // 2000-02-01 (Leap Year)
+        val state = DatePickerState(initialYear = 2000, initialMonth = 2, initialDay = 1)
+        assertEquals(29, state.maxDay)
+    }
+
+    @Test
+    fun testMaxDay_February_NonLeapYear_Century() {
+        // 1900-02-01 (Not a Leap Year)
+        val state = DatePickerState(initialYear = 1900, initialMonth = 2, initialDay = 1)
+        assertEquals(28, state.maxDay)
+    }
+
+    @Test
+    fun testMaxDay_April() {
+        // 2023-04-01
+        val state = DatePickerState(initialYear = 2023, initialMonth = 4, initialDay = 1)
+        assertEquals(30, state.maxDay)
+    }
+
+    @Test
+    fun testValidate_ClampsDay() {
+        // Start at Jan 31
+        val state = DatePickerState(initialYear = 2023, initialMonth = 1, initialDay = 31)
+        
+        // Change to Feb (Manual simulate state change since DatePickerState doesn't observe itself automatically unless in Composable)
+        // But here we are unit testing the class logic.
+        // We simulate "user changed month to 2". Max day becomes 28.
+        // Currently selected day is 31.
+        
+        // We update the backing state for month directly (mimicking Picker behavior)
+        state.monthState.selectedItem = 2
+        
+        // Assert maxDay is updated
+        assertEquals(28, state.maxDay)
+        
+        // Validate should clamp day to 28
+        state.validate()
+        
+        assertEquals(28, state.selectedDay)
+    }
+
+    @Test
+    fun testValidate_LeapYearChange() {
+        // Start at Feb 29, 2024 (Leap)
+        val state = DatePickerState(initialYear = 2024, initialMonth = 2, initialDay = 29)
+        assertEquals(29, state.maxDay)
+        
+        // Change Year to 2023 (Non-Leap)
+        state.yearState.selectedItem = 2023
+        
+        // Max day should be 28
+        assertEquals(28, state.maxDay)
+        
+        // Validate should clamp
+        state.validate()
+        
+        assertEquals(28, state.selectedDay)
+    }
+}
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/App.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/App.kt
index f59110a..180938d 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/App.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/App.kt
@@ -47,6 +47,11 @@ fun App() {
                 )
             }
             composable(Screen.DatePicker.route) {
+                YearMonthPickerSampleScreen(
+                    onBackPressed = { handleNavigateBack(navController) }
+                )
+            }
+            composable(Screen.DayPicker.route) {
                 DatePickerSampleScreen(
                     onBackPressed = { handleNavigateBack(navController) }
                 )
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/navigation/Screen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/navigation/Screen.kt
index ab4fdd9..9b32b6d 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/navigation/Screen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/navigation/Screen.kt
@@ -5,6 +5,7 @@ sealed class Screen(val route: String) {
     object Integrated : Screen("integrated")
     object TimePicker : Screen("time_picker")
     object DatePicker : Screen("date_picker")
+    object DayPicker : Screen("day_picker")
     object BottomSheet : Screen("bottom_sheet")
     object BackgroundStyle : Screen("background_style")
 }
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/DatePickerSampleScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/DatePickerSampleScreen.kt
index 5d79a23..bebd6e7 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/DatePickerSampleScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/DatePickerSampleScreen.kt
@@ -1,123 +1,120 @@
 package com.kez.picker.sample.ui.screen
 
-import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material3.Card
-import androidx.compose.material3.CardDefaults
-import androidx.compose.material3.CenterAlignedTopAppBar
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material.icons.filled.DateRange
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.derivedStateOf
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.text.font.FontWeight
-import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.sp
-import com.kez.picker.date.YearMonthPicker
-import com.kez.picker.rememberYearMonthPickerState
-import com.kez.picker.sample.getMonthName
-import com.kez.picker.util.currentDate
-import compose.icons.FeatherIcons
-import compose.icons.feathericons.ArrowLeft
-import compose.icons.feathericons.Calendar
-import kotlinx.datetime.number
+import com.kez.picker.date.DatePicker
+import com.kez.picker.rememberDatePickerState
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
-internal fun DatePickerSampleScreen(
-    onBackPressed: () -> Unit = {},
+fun DatePickerSampleScreen(
+    onBackPressed: () -> Unit
 ) {
-    val state = rememberYearMonthPickerState(
-        initialYear = currentDate.year,
-        initialMonth = currentDate.monthNumber
-    )
-
-    // Calculate selected date text
-    val selectedDateText by remember {
-        derivedStateOf {
-            "${state.selectedYear}년 ${getMonthName(state.selectedMonth)}"
-        }
-    }
-
     Scaffold(
         topBar = {
-            CenterAlignedTopAppBar(
-                title = { Text("DatePicker Sample", fontWeight = FontWeight.Bold) },
+            TopAppBar(
+                title = { Text("DatePicker Sample") },
                 navigationIcon = {
-                    IconButton(onClick = {
-                        onBackPressed()
-                    }) {
-                        Icon(FeatherIcons.ArrowLeft, contentDescription = "Back")
+                    IconButton(onClick = onBackPressed) {
+                        Icon(
+                            imageVector = Icons.Default.ArrowBack,
+                            contentDescription = "Back"
+                        )
                     }
-                }
+                },
+                colors = TopAppBarDefaults.topAppBarColors(
+                    containerColor = MaterialTheme.colorScheme.primaryContainer,
+                    titleContentColor = MaterialTheme.colorScheme.onPrimaryContainer
+                )
             )
         }
-    ) {
+    ) { paddingValues ->
         Column(
-            modifier = Modifier.fillMaxSize().padding(it).padding(16.dp),
-            horizontalAlignment = Alignment.CenterHorizontally,
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(paddingValues)
+                .padding(16.dp),
+            horizontalAlignment = Alignment.CenterHorizontally
         ) {
-            // Selected result display card
-            Card(
-                modifier = Modifier.fillMaxWidth(),
-                shape = RoundedCornerShape(12.dp),
-                elevation = CardDefaults.cardElevation(2.dp),
-                colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.primaryContainer)
+            val state = rememberDatePickerState()
+
+            Box(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .clip(RoundedCornerShape(16.dp))
+                    .background(MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.5f))
+                    .padding(24.dp)
             ) {
-                Row(
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .padding(16.dp),
-                    horizontalArrangement = Arrangement.Center,
-                    verticalAlignment = Alignment.CenterVertically
-                ) {
-                    Icon(
-                        imageVector = FeatherIcons.Calendar,
-                        contentDescription = "Selected date",
-                        tint = MaterialTheme.colorScheme.primary,
-                        modifier = Modifier.size(20.dp)
-                    )
-                    Spacer(modifier = Modifier.padding(horizontal = 8.dp))
-                    Text(
-                        text = "Selected date: $selectedDateText",
-                        fontSize = 16.sp,
-                        fontWeight = FontWeight.Medium,
-                        color = MaterialTheme.colorScheme.onSurface
-                    )
-                }
+                DatePicker(
+                    state = state,
+                    visibleItemsCount = 3,
+                    textStyle = MaterialTheme.typography.bodyLarge,
+                    selectedTextStyle = MaterialTheme.typography.headlineMedium.copy(
+                        color = MaterialTheme.colorScheme.primary
+                    ),
+                    dividerColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.5f)
+                )
             }
 
             Spacer(modifier = Modifier.height(32.dp))
 
-            YearMonthPicker(
-                modifier = Modifier.padding(horizontal = 12.dp),
-                state = state
-            )
-
-            // TODO: Add day selection capability
-            Spacer(modifier = Modifier.height(16.dp))
+            // Display Selected Value
+            Box(
+                modifier = Modifier
+                    .clip(RoundedCornerShape(8.dp))
+                    .background(MaterialTheme.colorScheme.secondaryContainer)
+                    .padding(16.dp)
+            ) {
+                Column(horizontalAlignment = Alignment.CenterHorizontally) {
+                    Text(
+                        text = "Selected Date",
+                        style = MaterialTheme.typography.labelLarge,
+                        color = MaterialTheme.colorScheme.onSecondaryContainer
+                    )
+                    Spacer(modifier = Modifier.height(8.dp))
+                    Row(verticalAlignment = Alignment.CenterVertically) {
+                        Icon(
+                            imageVector = Icons.Default.DateRange,
+                            contentDescription = null,
+                            tint = MaterialTheme.colorScheme.onSecondaryContainer
+                        )
+                        Spacer(modifier = Modifier.width(8.dp))
+                        Text(
+                            text = "${state.selectedYear}-${state.selectedMonth.toString().padStart(2, '0')}-${state.selectedDay.toString().padStart(2, '0')}",
+                            style = MaterialTheme.typography.headlineSmall,
+                            color = MaterialTheme.colorScheme.onSecondaryContainer
+                        )
+                    }
+                }
+            }
         }
     }
 }
 
-@Preview
-@Composable
-fun DatePickerSampleScreenPreview() {
-    DatePickerSampleScreen()
-}
\ No newline at end of file
+// Helper imports that might be missing
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.width
\ No newline at end of file
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/HomeScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/HomeScreen.kt
index 48ad530..fbcfefd 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/HomeScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/HomeScreen.kt
@@ -79,12 +79,20 @@ internal fun HomeScreen(navController: NavController) {
             }
             item {
                 MenuListItem(
-                    title = "DatePicker Sample",
+                    title = "YearMonthPicker Sample",
                     description = "Standalone YearMonthPicker component",
                     icon = FeatherIcons.Calendar,
                     onClick = { navController.navigate(Screen.DatePicker.route) }
                 )
             }
+            item {
+                MenuListItem(
+                    title = "DayPicker Sample",
+                    description = "Full DatePicker (Year, Month, Day)",
+                    icon = FeatherIcons.Calendar,
+                    onClick = { navController.navigate(Screen.DayPicker.route) }
+                )
+            }
             item {
                 MenuListItem(
                     title = "BottomSheet Sample",
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/YearMonthPickerSampleScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/YearMonthPickerSampleScreen.kt
new file mode 100644
index 0000000..cda0198
--- /dev/null
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/YearMonthPickerSampleScreen.kt
@@ -0,0 +1,121 @@
+package com.kez.picker.sample.ui.screen
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.CenterAlignedTopAppBar
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBarDefaults
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import com.kez.picker.date.YearMonthPicker
+import com.kez.picker.rememberYearMonthPickerState
+import com.kez.picker.sample.getMonthName
+import com.kez.picker.util.currentDate
+import compose.icons.FeatherIcons
+import compose.icons.feathericons.ArrowLeft
+import compose.icons.feathericons.Calendar
+import kotlinx.datetime.number
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+internal fun YearMonthPickerSampleScreen(
+    onBackPressed: () -> Unit = {},
+) {
+    val state = rememberYearMonthPickerState(
+        initialYear = currentDate.year,
+        initialMonth = currentDate.month.number
+    )
+
+    // Calculate selected date text
+    val selectedDateText by remember {
+        derivedStateOf {
+            "${state.selectedYear}년 ${getMonthName(state.selectedMonth)}"
+        }
+    }
+
+    Scaffold(
+        topBar = {
+            CenterAlignedTopAppBar(
+                title = { Text("YearMonthPicker Sample", fontWeight = FontWeight.Bold) },
+                navigationIcon = {
+                    IconButton(onClick = {
+                        onBackPressed()
+                    }) {
+                        Icon(FeatherIcons.ArrowLeft, contentDescription = "Back")
+                    }
+                },
+                colors = TopAppBarDefaults.centerAlignedTopAppBarColors(
+                    containerColor = Color.Transparent
+                )
+            )
+        }
+    ) {
+        Column(
+            modifier = Modifier.fillMaxSize().padding(it).padding(16.dp),
+            horizontalAlignment = Alignment.CenterHorizontally,
+        ) {
+            // Selected result display card
+            Card(
+                modifier = Modifier.fillMaxWidth(),
+                shape = RoundedCornerShape(12.dp),
+                elevation = CardDefaults.cardElevation(2.dp),
+                colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.primaryContainer)
+            ) {
+                Row(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .padding(16.dp),
+                    horizontalArrangement = Arrangement.Center,
+                    verticalAlignment = Alignment.CenterVertically
+                ) {
+                    Icon(
+                        imageVector = FeatherIcons.Calendar,
+                        contentDescription = "Selected date",
+                        tint = MaterialTheme.colorScheme.primary,
+                        modifier = Modifier.size(20.dp)
+                    )
+                    Spacer(modifier = Modifier.padding(horizontal = 8.dp))
+                    Text(
+                        text = "Selected date: $selectedDateText",
+                        fontSize = 16.sp,
+                        fontWeight = FontWeight.Medium,
+                        color = MaterialTheme.colorScheme.onSurface
+                    )
+                }
+            }
+
+            Spacer(modifier = Modifier.height(32.dp))
+
+            YearMonthPicker(
+                modifier = Modifier.padding(horizontal = 12.dp),
+                state = state
+            )
+            
+            Spacer(modifier = Modifier.height(16.dp))
+        }
+    }
+}

From a70fc00c400087f2b3bd9f1816da4ad65a05719d Mon Sep 17 00:00:00 2001
From: Kez <kejprogramer0909@gmail.com>
Date: Sat, 13 Dec 2025 17:13:28 +0900
Subject: [PATCH 2/9] =?UTF-8?q?refactor:=20Picker=20API=20=EA=B0=9C?=
 =?UTF-8?q?=EC=84=A0=20=EB=B0=8F=20=EC=A0=91=EA=B7=BC=EC=84=B1=20=EA=B0=95?=
 =?UTF-8?q?=ED=99=94?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../kotlin/com/kez/picker/Picker.kt           |  99 +++++++++++----
 .../kotlin/com/kez/picker/PickerDefaults.kt   | 118 ++++++++++++++++++
 .../kotlin/com/kez/picker/PickerState.kt      |  46 +++++--
 3 files changed, 228 insertions(+), 35 deletions(-)
 create mode 100644 datetimepicker/src/commonMain/kotlin/com/kez/picker/PickerDefaults.kt

diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt
index f751435..c9c0738 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt
@@ -27,7 +27,6 @@ import androidx.compose.runtime.snapshotFlow
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.drawWithContent
-import androidx.compose.ui.semantics.Role
 import androidx.compose.ui.graphics.BlendMode
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
@@ -36,12 +35,18 @@ import androidx.compose.ui.graphics.Shape
 import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.graphics.lerp
 import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.semantics.Role
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.role
+import androidx.compose.ui.semantics.selected
+import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.isSpecified
 import androidx.compose.ui.unit.lerp
 import androidx.compose.ui.unit.sp
 import kotlinx.coroutines.flow.distinctUntilChanged
@@ -49,6 +54,13 @@ import kotlinx.coroutines.flow.mapNotNull
 import kotlinx.coroutines.launch
 import kotlin.math.abs
 
+/**
+ * Multiplier for infinite scroll list size.
+ * Uses a reasonable multiplier instead of Int.MAX_VALUE to prevent memory issues
+ * while still providing a virtually infinite scrolling experience.
+ */
+private const val INFINITE_SCROLL_MULTIPLIER = 1000
+
 /**
  * A generic picker component that displays a list of items and allows the user to select one.
  *
@@ -97,6 +109,14 @@ fun <T> Picker(
     isInfinity: Boolean = true,
     content: @Composable ((T) -> Unit)? = null
 ) {
+    require(items.isNotEmpty()) { "Items list must not be empty" }
+    require(visibleItemsCount > 0 && visibleItemsCount % 2 == 1) {
+        "visibleItemsCount must be a positive odd number, but was $visibleItemsCount"
+    }
+    require(startIndex >= 0 && startIndex < items.size) {
+        "startIndex must be in range [0, ${items.size}), but was $startIndex"
+    }
+
     val density = LocalDensity.current
     val visibleItemsMiddle = remember { visibleItemsCount / 2 }
     val scope = rememberCoroutineScope()
@@ -108,33 +128,43 @@ fun <T> Picker(
     }
 
     val listScrollCount = if (isInfinity) {
-        Int.MAX_VALUE
+        adjustedItems.size * INFINITE_SCROLL_MULTIPLIER
     } else {
         adjustedItems.size
     }
 
-    val listScrollMiddle = remember { listScrollCount / 2 }
-    val listStartIndex = remember {
-        if (isInfinity) {
-            listScrollMiddle - listScrollMiddle % adjustedItems.size - visibleItemsMiddle + startIndex
-        } else {
-            startIndex + 1
+    val listScrollMiddle = remember(listScrollCount) { listScrollCount / 2 }
+    val listStartIndex =
+        remember(listScrollCount, adjustedItems.size, visibleItemsMiddle, startIndex) {
+            if (isInfinity) {
+                listScrollMiddle - listScrollMiddle % adjustedItems.size - visibleItemsMiddle + startIndex
+            } else {
+                startIndex + 1
+            }
         }
-    }
 
     fun getItem(index: Int) = adjustedItems[index % adjustedItems.size]
 
     val listState = rememberLazyListState(initialFirstVisibleItemIndex = listStartIndex)
     val flingBehavior = rememberSnapFlingBehavior(lazyListState = listState)
 
+    val selectedLineHeight = selectedTextStyle.lineHeight.takeIf { it.isSpecified } ?: 0.sp
+    val unselectedLineHeight = textStyle.lineHeight.takeIf { it.isSpecified } ?: 0.sp
+    val largestLineHeight =
+        if (selectedLineHeight > unselectedLineHeight) selectedLineHeight else unselectedLineHeight
+
+    val selectedFontSize = selectedTextStyle.fontSize.takeIf { it.isSpecified } ?: 0.sp
+    val unselectedFontSize = textStyle.fontSize.takeIf { it.isSpecified } ?: 0.sp
+    val largestFontSize =
+        if (selectedFontSize > unselectedFontSize) selectedFontSize else unselectedFontSize
+
+    val textHeightSp = if (largestLineHeight > 0.sp) largestLineHeight else largestFontSize
+
     val itemHeight = with(density) {
-        selectedTextStyle.fontSize
-            .toPx()
-            .toDp()
-            .plus(itemPadding.calculateTopPadding())
-            .plus(itemPadding.calculateBottomPadding())
+        textHeightSp.toDp() +
+                itemPadding.calculateTopPadding() +
+                itemPadding.calculateBottomPadding()
     }
-
     LaunchedEffect(listState) {
         snapshotFlow { listState.firstVisibleItemIndex }
             .mapNotNull { index -> getItem(index + visibleItemsMiddle) }
@@ -179,6 +209,9 @@ fun <T> Picker(
                 )
             }
         }
+
+        val sharedInteractionSource = remember { MutableInteractionSource() }
+
         LazyColumn(
             state = listState,
             flingBehavior = flingBehavior,
@@ -207,18 +240,28 @@ fun <T> Picker(
                 }
 
                 val item = getItem(index)
-                
+                val isSelected = item == state.selectedItem
+                val itemDescription = item?.toString() ?: ""
+
                 Box(
                     modifier = Modifier
                         .height(itemHeight)
                         .fillMaxWidth()
+                        .semantics {
+                            if (item != null) {
+                                role = Role.Button
+                                contentDescription = itemDescription
+                                selected = isSelected
+                            }
+                        }
                         .clickable(
                             enabled = item != null,
                             role = Role.Button,
                             indication = null,
-                            interactionSource = remember { MutableInteractionSource() },
+                            interactionSource = sharedInteractionSource,
                             onClick = {
-                                val currentCenterIndex = listState.firstVisibleItemIndex + visibleItemsMiddle
+                                val currentCenterIndex =
+                                    listState.firstVisibleItemIndex + visibleItemsMiddle
                                 if (index != currentCenterIndex) {
                                     scope.launch {
                                         val targetIndex = (index - visibleItemsMiddle)
@@ -235,20 +278,27 @@ fun <T> Picker(
                         if (content != null) {
                             content(item)
                         } else {
+                            val baseColor = LocalContentColor.current
+                            val selectedColor =
+                                if (selectedTextStyle.color == Color.Unspecified) baseColor else selectedTextStyle.color
+
+                            val normalColor =
+                                if (textStyle.color == Color.Unspecified) baseColor.copy(alpha = 0.7f) else textStyle.color
+
                             Text(
-                                text = item.toString(),
+                                text = itemDescription,
                                 maxLines = 1,
                                 overflow = TextOverflow.Ellipsis,
                                 style = textStyle.copy(
                                     fontSize = lerp(
-                                        selectedTextStyle.fontSize,
-                                        textStyle.fontSize,
+                                        start = selectedTextStyle.fontSize,
+                                        stop = textStyle.fontSize,
                                         fraction
                                     ),
                                     color = lerp(
-                                        selectedTextStyle.color,
-                                        textStyle.color,
-                                        fraction
+                                        start = selectedColor,
+                                        stop = normalColor,
+                                        fraction = fraction
                                     ),
                                 ),
                                 textAlign = TextAlign.Center
@@ -260,6 +310,7 @@ fun <T> Picker(
         }
     }
 }
+
 /**
  * Apply a fading edge effect to a modifier.
  *
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/PickerDefaults.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/PickerDefaults.kt
new file mode 100644
index 0000000..68742d9
--- /dev/null
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/PickerDefaults.kt
@@ -0,0 +1,118 @@
+package com.kez.picker
+
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.LocalContentColor
+import androidx.compose.material3.LocalTextStyle
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Immutable
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.Shape
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+
+/**
+ * Contains default values and factory methods for creating Picker styles.
+ */
+object PickerDefaults {
+
+    /**
+     * Default number of visible items in the picker.
+     */
+    const val VisibleItemsCount: Int = 3
+
+    /**
+     * Default padding around each item.
+     */
+    val ItemPadding: PaddingValues = PaddingValues(8.dp)
+
+    /**
+     * Default thickness of the dividers.
+     */
+    val DividerThickness: Dp = 1.dp
+
+    /**
+     * Default spacing between pickers in composite components (e.g., TimePicker).
+     */
+    val SpacingBetweenPickers: Dp = 20.dp
+
+    /**
+     * Default shape for the selected item background.
+     */
+    val SelectedItemBackgroundShape: Shape = RoundedCornerShape(12.dp)
+
+    /**
+     * Default shape for the dividers.
+     */
+    val DividerShape: Shape = RoundedCornerShape(10.dp)
+
+    /**
+     * Creates a [PickerColors] with the provided colors.
+     *
+     * @param dividerColor The color of the dividers.
+     * @param selectedItemBackgroundColor The background color of the selected item area.
+     * @return A [PickerColors] instance with the specified colors.
+     */
+    @Composable
+    fun colors(
+        dividerColor: Color = LocalContentColor.current,
+        selectedItemBackgroundColor: Color = Color.Transparent
+    ): PickerColors = PickerColors(
+        dividerColor = dividerColor,
+        selectedItemBackgroundColor = selectedItemBackgroundColor
+    )
+
+    /**
+     * Creates a [PickerTextStyles] with the provided text styles.
+     *
+     * @param textStyle The style of the text for unselected items.
+     * @param selectedTextStyle The style of the text for the selected item.
+     * @return A [PickerTextStyles] instance with the specified styles.
+     */
+    @Composable
+    fun textStyles(
+        textStyle: TextStyle = LocalTextStyle.current.copy(fontSize = 16.sp),
+        selectedTextStyle: TextStyle = LocalTextStyle.current.copy(fontSize = 22.sp)
+    ): PickerTextStyles = PickerTextStyles(
+        textStyle = textStyle,
+        selectedTextStyle = selectedTextStyle
+    )
+
+    /**
+     * Creates the default fading edge gradient.
+     *
+     * @return A vertical [Brush] with transparent edges and opaque center.
+     */
+    fun fadingEdgeGradient(): Brush = Brush.verticalGradient(
+        0f to Color.Transparent,
+        0.5f to Color.Black,
+        1f to Color.Transparent
+    )
+}
+
+/**
+ * Represents the colors used by [Picker] and related components.
+ *
+ * @param dividerColor The color of the dividers.
+ * @param selectedItemBackgroundColor The background color of the selected item area.
+ */
+@Immutable
+data class PickerColors(
+    val dividerColor: Color,
+    val selectedItemBackgroundColor: Color
+)
+
+/**
+ * Represents the text styles used by [Picker] and related components.
+ *
+ * @param textStyle The style of the text for unselected items.
+ * @param selectedTextStyle The style of the text for the selected item.
+ */
+@Immutable
+data class PickerTextStyles(
+    val textStyle: TextStyle,
+    val selectedTextStyle: TextStyle
+)
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/PickerState.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/PickerState.kt
index 8b316d7..4ce6cb7 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/PickerState.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/PickerState.kt
@@ -25,6 +25,9 @@ fun <T> rememberPickerState(initialItem: T) = remember { PickerState(initialItem
 /**
  * State holder for the picker component.
  *
+ * The [selectedItem] property is read-only from external code.
+ * Item selection is managed internally by the [Picker] component through scrolling.
+ *
  * @param initialItem The initial selected item.
  */
 @Stable
@@ -33,8 +36,10 @@ class PickerState<T>(
 ) {
     /**
      * The currently selected item.
+     * This value is updated internally when the user scrolls the picker.
      */
-    var selectedItem by mutableStateOf(initialItem)
+    var selectedItem: T by mutableStateOf(initialItem)
+        internal set
 }
 
 /**
@@ -46,8 +51,8 @@ class PickerState<T>(
  */
 @Composable
 fun rememberYearMonthPickerState(
-    initialYear: Int = currentDate.year,
-    initialMonth: Int = currentDate.month.number
+    initialYear: Int = currentDate().year,
+    initialMonth: Int = currentDate().month.number
 ): YearMonthPickerState {
     return remember(initialYear, initialMonth) {
         YearMonthPickerState(initialYear, initialMonth)
@@ -58,6 +63,7 @@ fun rememberYearMonthPickerState(
  * State holder for the [com.kez.picker.date.YearMonthPicker].
  *
  * Manages the state of the year and month pickers.
+ * Internal picker states are not directly accessible to prevent inconsistent state modifications.
  *
  * @param initialYear The initial year to be selected.
  * @param initialMonth The initial month to be selected.
@@ -67,12 +73,18 @@ class YearMonthPickerState(
     initialYear: Int,
     initialMonth: Int
 ) {
-    val yearState = PickerState(initialYear)
-    val monthState = PickerState(initialMonth)
+    internal val yearState = PickerState(initialYear)
+    internal val monthState = PickerState(initialMonth)
 
+    /**
+     * The currently selected year.
+     */
     val selectedYear: Int
         get() = yearState.selectedItem
 
+    /**
+     * The currently selected month (1-12).
+     */
     val selectedMonth: Int
         get() = monthState.selectedItem
 }
@@ -89,8 +101,8 @@ class YearMonthPickerState(
  */
 @Composable
 fun rememberTimePickerState(
-    initialHour: Int = currentHour,
-    initialMinute: Int = currentMinute,
+    initialHour: Int = currentHour(),
+    initialMinute: Int = currentMinute(),
     initialPeriod: TimePeriod = if (initialHour >= 12) TimePeriod.PM else TimePeriod.AM,
     timeFormat: TimeFormat = TimeFormat.HOUR_24
 ): TimePickerState {
@@ -116,6 +128,7 @@ fun rememberTimePickerState(
  * State holder for the [TimePicker].
  *
  * Manages the state of the hour, minute, and period (AM/PM) pickers.
+ * Internal picker states are not directly accessible to prevent inconsistent state modifications.
  *
  * @param initialHour The initial hour to be selected.
  * @param initialMinute The initial minute to be selected.
@@ -129,16 +142,27 @@ class TimePickerState(
     initialPeriod: TimePeriod,
     val timeFormat: TimeFormat
 ) {
-    val hourState = PickerState(initialHour)
-    val minuteState = PickerState(initialMinute)
-    val periodState = PickerState(initialPeriod)
+    internal val hourState = PickerState(initialHour)
+    internal val minuteState = PickerState(initialMinute)
+    internal val periodState = PickerState(initialPeriod)
 
+    /**
+     * The currently selected hour.
+     * For 12-hour format: 1-12, for 24-hour format: 0-23.
+     */
     val selectedHour: Int
         get() = hourState.selectedItem
 
+    /**
+     * The currently selected minute (0-59).
+     */
     val selectedMinute: Int
         get() = minuteState.selectedItem
 
+    /**
+     * The currently selected period (AM/PM).
+     * Only relevant when using 12-hour format.
+     */
     val selectedPeriod: TimePeriod
         get() = periodState.selectedItem
-}
\ No newline at end of file
+}

From 5bd74788cf56dc4939a8f6901943e0bd6d1d404b Mon Sep 17 00:00:00 2001
From: Kez <kejprogramer0909@gmail.com>
Date: Sat, 13 Dec 2025 17:14:04 +0900
Subject: [PATCH 3/9] =?UTF-8?q?fix:=20TimeUtil=20=EC=8B=A4=EC=8B=9C?=
 =?UTF-8?q?=EA=B0=84=20=EC=8B=9C=EA=B0=84=20=EB=B0=98=EC=98=81=20=EB=B0=8F?=
 =?UTF-8?q?=20TimePicker=20=EC=A0=81=EC=9A=A9?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../kotlin/com/kez/picker/time/TimePicker.kt  |  3 +-
 .../com/kez/picker/util/TimeCalculation.kt    |  9 ++--
 .../kotlin/com/kez/picker/util/TimeUtil.kt    | 47 +++++++++++++------
 .../kez/picker/util/TimeCalculationTest.kt    | 10 ++--
 .../ui/screen/TimePickerSampleScreen.kt       |  3 ++
 5 files changed, 46 insertions(+), 26 deletions(-)

diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt
index 75a00ec..2a0b885 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt
@@ -31,7 +31,6 @@ import com.kez.picker.util.MINUTE_RANGE
 import com.kez.picker.util.TimeFormat
 import com.kez.picker.util.TimePeriod
 import com.kez.picker.util.currentDateTime
-import kotlinx.datetime.LocalDateTime
 
 /**
  * A time picker component that allows the user to select hours, minutes, and—when using the 12-hour format—the AM/PM period.
@@ -63,7 +62,7 @@ fun TimePicker(
     modifier: Modifier = Modifier,
     pickerModifier: Modifier = Modifier,
     state: TimePickerState = rememberTimePickerState(),
-    startTime: LocalDateTime = currentDateTime,
+    startTime: kotlinx.datetime.LocalDateTime = currentDateTime(),
     minuteItems: List<Int> = MINUTE_RANGE,
     hourItems: List<Int> = when (state.timeFormat) {
         TimeFormat.HOUR_12 -> HOUR12_RANGE
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/util/TimeCalculation.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/util/TimeCalculation.kt
index 49977dc..dac4146 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/util/TimeCalculation.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/util/TimeCalculation.kt
@@ -29,11 +29,12 @@ fun calculateTime(
         TimeFormat.HOUR_24 -> hour
     }
 
+    val now = currentDateTime()
     return LocalDateTime(
-        year = currentYear,
-        month = currentMonth,
-        day = currentDate.day,
+        year = now.year,
+        month = now.month,
+        day = now.date.day,
         hour = adjustHour.coerceIn(0, 23),
         minute = minute.coerceIn(0, 59)
     )
-} 
\ No newline at end of file
+}
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/util/TimeUtil.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/util/TimeUtil.kt
index 325abad..c531ed1 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/util/TimeUtil.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/util/TimeUtil.kt
@@ -3,6 +3,8 @@
 package com.kez.picker.util
 
 import kotlin.time.Clock
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.LocalDateTime
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.number
 import kotlinx.datetime.toLocalDateTime
@@ -33,34 +35,49 @@ val HOUR12_RANGE = (1..12).toList()
 val MINUTE_RANGE = (0..59).toList()
 
 /**
- * Current date and time.
+ * Returns the current date and time.
+ * This function is called each time to get the actual current time,
+ * preventing stale time values in long-running applications.
+ *
+ * @return The current [LocalDateTime] in the system's default timezone.
  */
-val currentDateTime = Clock.System.now().toLocalDateTime(TimeZone.currentSystemDefault())
+fun currentDateTime(): LocalDateTime =
+    Clock.System.now().toLocalDateTime(TimeZone.currentSystemDefault())
 
 /**
- * Current date.
+ * Returns the current date.
+ *
+ * @return The current [LocalDate].
  */
-val currentDate = currentDateTime.date
+fun currentDate(): LocalDate = currentDateTime().date
 
 /**
- * Current year.
+ * Returns the current year.
+ *
+ * @return The current year as an [Int].
  */
-val currentYear = currentDateTime.year
+fun currentYear(): Int = currentDateTime().year
 
 /**
- * Current month number (1-12).
+ * Returns the current month number (1-12).
+ *
+ * @return The current month number as an [Int].
  */
-val currentMonth = currentDateTime.month.number
+fun currentMonth(): Int = currentDateTime().month.number
 
 /**
- * Current minute (0-59).
+ * Returns the current minute (0-59).
+ *
+ * @return The current minute as an [Int].
  */
-val currentMinute = currentDateTime.minute
+fun currentMinute(): Int = currentDateTime().minute
 
 /**
- * Current hour (0-23).
+ * Returns the current hour (0-23).
+ *
+ * @return The current hour as an [Int].
  */
-val currentHour = currentDateTime.hour
+fun currentHour(): Int = currentDateTime().hour
 
 /**
  * Time format for time picker.
@@ -70,7 +87,7 @@ enum class TimeFormat {
      * 12-hour format (AM/PM).
      */
     HOUR_12,
-    
+
     /**
      * 24-hour format.
      */
@@ -85,9 +102,9 @@ enum class TimePeriod {
      * AM period (Ante Meridiem).
      */
     AM,
-    
+
     /**
      * PM period (Post Meridiem).
      */
     PM
-} 
\ No newline at end of file
+}
diff --git a/datetimepicker/src/commonTest/kotlin/com/kez/picker/util/TimeCalculationTest.kt b/datetimepicker/src/commonTest/kotlin/com/kez/picker/util/TimeCalculationTest.kt
index 5789347..323dc33 100644
--- a/datetimepicker/src/commonTest/kotlin/com/kez/picker/util/TimeCalculationTest.kt
+++ b/datetimepicker/src/commonTest/kotlin/com/kez/picker/util/TimeCalculationTest.kt
@@ -16,7 +16,7 @@ class TimeCalculationTest {
     private val testDate: LocalDate = Clock.System.now().toLocalDateTime(TimeZone.currentSystemDefault()).date
     private val currentYear: Int = testDate.year
     private val currentMonth: Int = testDate.month.number
-    private val currentDate: LocalDate = testDate
+    private val currentDay: Int = testDate.day
 
     // 24시간 형식에서 23:45 입력 시 동일한 시간이 반환되는지 확인
     @Test
@@ -30,7 +30,7 @@ class TimeCalculationTest {
         val expected = LocalDateTime(
             year = currentYear,
             month = currentMonth,
-            day = currentDate.day,
+            day = currentDay,
             hour = 23,
             minute = 45
         )
@@ -51,7 +51,7 @@ class TimeCalculationTest {
         val expected = LocalDateTime(
             year = currentYear,
             month = currentMonth,
-            day = currentDate.day,
+            day = currentDay,
             hour = 15,
             minute = 15
         )
@@ -72,7 +72,7 @@ class TimeCalculationTest {
         val expected = LocalDateTime(
             year = currentYear,
             month = currentMonth,
-            day = currentDate.day,
+            day = currentDay,
             hour = 0,
             minute = 0
         )
@@ -93,7 +93,7 @@ class TimeCalculationTest {
         val expected = LocalDateTime(
             year = currentYear,
             month = currentMonth,
-            day = currentDate.day,
+            day = currentDay,
             hour = 12,
             minute = 30
         )
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/TimePickerSampleScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/TimePickerSampleScreen.kt
index f0df747..e278567 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/TimePickerSampleScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/TimePickerSampleScreen.kt
@@ -54,6 +54,9 @@ internal fun TimePickerSampleScreen(
     onBackPressed: () -> Unit = {},
 ) {
     var selectedFormat by remember { mutableIntStateOf(0) }
+    val currentHour = currentHour()
+    val currentMinute = currentMinute()
+
     val timeState12 = rememberTimePickerState(
         initialHour = currentHour,
         initialMinute = currentMinute,

From cb5c5d90576c04ff9f8b835b7e68cb9f49995353 Mon Sep 17 00:00:00 2001
From: Kez <kejprogramer0909@gmail.com>
Date: Sat, 13 Dec 2025 17:16:33 +0900
Subject: [PATCH 4/9] =?UTF-8?q?feat:=20DatePicker=20=EC=BB=B4=ED=8F=AC?=
 =?UTF-8?q?=EB=84=8C=ED=8A=B8=20=EC=B6=94=EA=B0=80=20=EB=B0=8F=20Date=20?=
 =?UTF-8?q?=EA=B4=80=EB=A0=A8=20=EB=A1=9C=EC=A7=81=20=EA=B0=9C=EC=84=A0?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../kotlin/com/kez/picker/date/DatePicker.kt  | 44 ++++++-----
 .../com/kez/picker/date/DatePickerState.kt    | 54 +++++++------
 .../com/kez/picker/date/YearMonthPicker.kt    |  3 +-
 .../kez/picker/date/DatePickerStateTest.kt    | 79 +++++++++++--------
 4 files changed, 99 insertions(+), 81 deletions(-)

diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
index 263912a..7f8ae06 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
@@ -10,6 +10,7 @@ import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.LocalContentColor
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.key
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -27,7 +28,6 @@ import com.kez.picker.rememberDatePickerState
 import com.kez.picker.util.MONTH_RANGE
 import com.kez.picker.util.YEAR_RANGE
 import com.kez.picker.util.currentDate
-import kotlinx.datetime.LocalDate
 import kotlinx.datetime.number
 
 /**
@@ -59,7 +59,7 @@ fun DatePicker(
     modifier: Modifier = Modifier,
     pickerModifier: Modifier = Modifier,
     state: DatePickerState = rememberDatePickerState(),
-    startLocalDate: LocalDate = currentDate,
+    startLocalDate: kotlinx.datetime.LocalDate = currentDate(),
     yearItems: List<Int> = YEAR_RANGE,
     monthItems: List<Int> = MONTH_RANGE,
     visibleItemsCount: Int = 3,
@@ -161,25 +161,27 @@ fun DatePicker(
                 )
 
                 // Day Picker
-                Picker(
-                    state = state.dayState,
-                    items = dayItems,
-                    startIndex = dayStartIndex,
-                    visibleItemsCount = visibleItemsCount,
-                    modifier = pickerModifier.weight(0.8f),
-                    textStyle = textStyle,
-                    selectedTextStyle = selectedTextStyle,
-                    dividerColor = dividerColor,
-                    selectedItemBackgroundColor = selectedItemBackgroundColor,
-                    selectedItemBackgroundShape = selectedItemBackgroundShape,
-                    itemPadding = itemPadding,
-                    fadingEdgeGradient = fadingEdgeGradient,
-                    horizontalAlignment = horizontalAlignment,
-                    itemTextAlignment = verticalAlignment,
-                    dividerThickness = dividerThickness,
-                    dividerShape = dividerShape,
-                    isDividerVisible = isDividerVisible,
-                )
+                key(maxDay) {
+                    Picker(
+                        state = state.dayState,
+                        items = dayItems,
+                        startIndex = dayStartIndex,
+                        visibleItemsCount = visibleItemsCount,
+                        modifier = pickerModifier.weight(0.8f),
+                        textStyle = textStyle,
+                        selectedTextStyle = selectedTextStyle,
+                        dividerColor = dividerColor,
+                        selectedItemBackgroundColor = selectedItemBackgroundColor,
+                        selectedItemBackgroundShape = selectedItemBackgroundShape,
+                        itemPadding = itemPadding,
+                        fadingEdgeGradient = fadingEdgeGradient,
+                        horizontalAlignment = horizontalAlignment,
+                        itemTextAlignment = verticalAlignment,
+                        dividerThickness = dividerThickness,
+                        dividerShape = dividerShape,
+                        isDividerVisible = isDividerVisible,
+                    )
+                }
             }
         }
     }
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePickerState.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePickerState.kt
index 0d935d9..6a25603 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePickerState.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePickerState.kt
@@ -4,7 +4,6 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.Stable
 import androidx.compose.runtime.remember
 import com.kez.picker.util.currentDate
-import kotlinx.datetime.LocalDate
 import kotlinx.datetime.number
 
 /**
@@ -17,9 +16,9 @@ import kotlinx.datetime.number
  */
 @Composable
 fun rememberDatePickerState(
-    initialYear: Int = currentDate.year,
-    initialMonth: Int = currentDate.month.number,
-    initialDay: Int = currentDate.day
+    initialYear: Int = currentDate().year,
+    initialMonth: Int = currentDate().month.number,
+    initialDay: Int = currentDate().day
 ): DatePickerState {
     return remember(initialYear, initialMonth, initialDay) {
         DatePickerState(initialYear, initialMonth, initialDay)
@@ -31,6 +30,7 @@ fun rememberDatePickerState(
  *
  * Manages the state of the year, month, and day pickers.
  * Automatically adjusts the selected day if it exceeds the maximum valid day for the new year/month.
+ * Internal picker states are not directly accessible to prevent inconsistent state modifications.
  *
  * @param initialYear The initial year to be selected.
  * @param initialMonth The initial month to be selected.
@@ -42,16 +42,25 @@ class DatePickerState(
     initialMonth: Int,
     initialDay: Int
 ) {
-    val yearState = PickerState(initialYear)
-    val monthState = PickerState(initialMonth)
-    val dayState = PickerState(initialDay)
+    internal val yearState = PickerState(initialYear)
+    internal val monthState = PickerState(initialMonth)
+    internal val dayState = PickerState(initialDay)
 
+    /**
+     * The currently selected year.
+     */
     val selectedYear: Int
         get() = yearState.selectedItem
 
+    /**
+     * The currently selected month (1-12).
+     */
     val selectedMonth: Int
         get() = monthState.selectedItem
 
+    /**
+     * The currently selected day (1-31).
+     */
     val selectedDay: Int
         get() = dayState.selectedItem
 
@@ -63,31 +72,26 @@ class DatePickerState(
         get() = daysInMonth(selectedYear, selectedMonth)
 
     init {
-        // Ensure initial day is valid
-        if (initialDay > maxDay) {
-            dayState.selectedItem = maxDay
+        val initialMaxDay = daysInMonth(initialYear, initialMonth)
+        if (initialDay > initialMaxDay) {
+            dayState.selectedItem = initialMaxDay
         }
     }
-    
-    // We need to observe changes to year/month to clamp the day
-    // However, PickerState updates are independent composable states.
-    // In strict Compose, we should probably use derivedStateOf or side-effects in the composable calling this.
-    // But since PickerState internal `selectedItem` is mutableStateOf, 
-    // we can try to hook into the validation in the UI layer or make this class reactive.
-    // For simplicity with existing PickerState pattern:
-    // The UI (DatePicker) should observe selectedYear/selectedMonth and update the day picker's range/value if needed.
-    // OR we expose a function to validation.
-    
-    // Actually, simply querying `maxDay` in the UI to limit the list of days is the best approach.
-    // But we also need to clamp the *selected* value if it goes out of range.
-    // Let's add a function to validate and adjust.
-    fun validate() {
+
+    /**
+     * Validates and adjusts the selected day if it exceeds the maximum valid day
+     * for the currently selected year and month.
+     *
+     * This function should be called when the year or month changes to ensure
+     * the day remains valid (e.g., Feb 30 -> Feb 28/29).
+     */
+    internal fun validate() {
         val currentMax = maxDay
         if (dayState.selectedItem > currentMax) {
             dayState.selectedItem = currentMax
         }
     }
-    
+
     private fun daysInMonth(year: Int, month: Int): Int {
         return when (month) {
             1, 3, 5, 7, 8, 10, 12 -> 31
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt
index 07ec07d..4c94757 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt
@@ -26,7 +26,6 @@ import com.kez.picker.rememberYearMonthPickerState
 import com.kez.picker.util.MONTH_RANGE
 import com.kez.picker.util.YEAR_RANGE
 import com.kez.picker.util.currentDate
-import kotlinx.datetime.LocalDate
 import kotlinx.datetime.number
 
 /**
@@ -59,7 +58,7 @@ fun YearMonthPicker(
     modifier: Modifier = Modifier,
     pickerModifier: Modifier = Modifier,
     state: YearMonthPickerState = rememberYearMonthPickerState(),
-    startLocalDate: LocalDate = currentDate,
+    startLocalDate: kotlinx.datetime.LocalDate = currentDate(),
     yearItems: List<Int> = YEAR_RANGE,
     monthItems: List<Int> = MONTH_RANGE,
     visibleItemsCount: Int = 3,
diff --git a/datetimepicker/src/commonTest/kotlin/com/kez/picker/date/DatePickerStateTest.kt b/datetimepicker/src/commonTest/kotlin/com/kez/picker/date/DatePickerStateTest.kt
index ba112d5..0de6d63 100644
--- a/datetimepicker/src/commonTest/kotlin/com/kez/picker/date/DatePickerStateTest.kt
+++ b/datetimepicker/src/commonTest/kotlin/com/kez/picker/date/DatePickerStateTest.kt
@@ -49,42 +49,55 @@ class DatePickerStateTest {
     }
 
     @Test
-    fun testValidate_ClampsDay() {
-        // Start at Jan 31
-        val state = DatePickerState(initialYear = 2023, initialMonth = 1, initialDay = 31)
-        
-        // Change to Feb (Manual simulate state change since DatePickerState doesn't observe itself automatically unless in Composable)
-        // But here we are unit testing the class logic.
-        // We simulate "user changed month to 2". Max day becomes 28.
-        // Currently selected day is 31.
-        
-        // We update the backing state for month directly (mimicking Picker behavior)
-        state.monthState.selectedItem = 2
-        
-        // Assert maxDay is updated
-        assertEquals(28, state.maxDay)
-        
-        // Validate should clamp day to 28
-        state.validate()
-        
+    fun testInitialDay_Clamped_WhenExceedsMaxDay() {
+        // Trying to set Feb 30 should be clamped to Feb 28
+        val state = DatePickerState(initialYear = 2023, initialMonth = 2, initialDay = 30)
         assertEquals(28, state.selectedDay)
     }
 
     @Test
-    fun testValidate_LeapYearChange() {
-        // Start at Feb 29, 2024 (Leap)
-        val state = DatePickerState(initialYear = 2024, initialMonth = 2, initialDay = 29)
-        assertEquals(29, state.maxDay)
-        
-        // Change Year to 2023 (Non-Leap)
-        state.yearState.selectedItem = 2023
-        
-        // Max day should be 28
-        assertEquals(28, state.maxDay)
-        
-        // Validate should clamp
-        state.validate()
-        
-        assertEquals(28, state.selectedDay)
+    fun testInitialDay_Clamped_LeapYear() {
+        // Trying to set Feb 30 on leap year should be clamped to Feb 29
+        val state = DatePickerState(initialYear = 2024, initialMonth = 2, initialDay = 30)
+        assertEquals(29, state.selectedDay)
+    }
+
+    @Test
+    fun testSelectedValues_MatchInitialValues() {
+        val state = DatePickerState(initialYear = 2025, initialMonth = 6, initialDay = 15)
+        assertEquals(2025, state.selectedYear)
+        assertEquals(6, state.selectedMonth)
+        assertEquals(15, state.selectedDay)
+    }
+
+    @Test
+    fun testMaxDay_AllMonths() {
+        val daysInMonth = mapOf(
+            1 to 31, 2 to 28, 3 to 31, 4 to 30,
+            5 to 31, 6 to 30, 7 to 31, 8 to 31,
+            9 to 30, 10 to 31, 11 to 30, 12 to 31
+        )
+
+        daysInMonth.forEach { (month, expectedDays) ->
+            val state = DatePickerState(initialYear = 2023, initialMonth = month, initialDay = 1)
+            assertEquals(expectedDays, state.maxDay, "Month $month should have $expectedDays days")
+        }
+    }
+
+    @Test
+    fun testMaxDay_February_LeapYearVariations() {
+        // Test various leap years
+        val leapYears = listOf(2000, 2004, 2020, 2024, 2400)
+        val nonLeapYears = listOf(1900, 2100, 2023, 2025)
+
+        leapYears.forEach { year ->
+            val state = DatePickerState(initialYear = year, initialMonth = 2, initialDay = 1)
+            assertEquals(29, state.maxDay, "Year $year should be a leap year with 29 days in Feb")
+        }
+
+        nonLeapYears.forEach { year ->
+            val state = DatePickerState(initialYear = year, initialMonth = 2, initialDay = 1)
+            assertEquals(28, state.maxDay, "Year $year should not be a leap year with 28 days in Feb")
+        }
     }
 }

From 8e5236bea8a373ce6c938c73a7dc2ad0d8b33f8b Mon Sep 17 00:00:00 2001
From: Kez <kejprogramer0909@gmail.com>
Date: Sat, 13 Dec 2025 17:21:33 +0900
Subject: [PATCH 5/9] =?UTF-8?q?feat:=20Sample=20App=20=EC=97=85=EB=8D=B0?=
 =?UTF-8?q?=EC=9D=B4=ED=8A=B8=20(DatePicker=20=EC=B6=94=EA=B0=80=20?=
 =?UTF-8?q?=EB=B0=8F=20=EB=8F=99=EC=9E=91=20=EA=B0=9C=EC=84=A0)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../kotlin/com/kez/picker/sample/App.kt       |  1 +
 .../ui/screen/BackgroundStylePickerScreen.kt  |  7 +++--
 .../ui/screen/BottomSheetSampleScreen.kt      |  7 +++--
 .../ui/screen/DatePickerSampleScreen.kt       | 31 ++++++++++---------
 .../ui/screen/IntegratedPickerScreen.kt       |  4 +++
 .../ui/screen/YearMonthPickerSampleScreen.kt  |  4 +--
 6 files changed, 32 insertions(+), 22 deletions(-)

diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/App.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/App.kt
index 180938d..7e4ade1 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/App.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/App.kt
@@ -14,6 +14,7 @@ import com.kez.picker.sample.ui.screen.DatePickerSampleScreen
 import com.kez.picker.sample.ui.screen.HomeScreen
 import com.kez.picker.sample.ui.screen.IntegratedPickerScreen
 import com.kez.picker.sample.ui.screen.TimePickerSampleScreen
+import com.kez.picker.sample.ui.screen.YearMonthPickerSampleScreen
 import com.kez.picker.sample.ui.theme.AppTheme
 
 @Composable
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BackgroundStylePickerScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BackgroundStylePickerScreen.kt
index d241513..8fe6c90 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BackgroundStylePickerScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BackgroundStylePickerScreen.kt
@@ -51,12 +51,13 @@ internal fun BackgroundStylePickerScreen(
     onBackPressed: () -> Unit = {},
 ) {
     val yearMonthState = rememberYearMonthPickerState(
-        initialYear = currentDate.year,
-        initialMonth = currentDate.monthNumber
+        initialYear = currentDate().year,
+        initialMonth = currentDate().month.number
     )
+    val currentHour = currentHour()
     val timeState = rememberTimePickerState(
         initialHour = currentHour,
-        initialMinute = currentMinute,
+        initialMinute = currentMinute(),
         initialPeriod = if (currentHour >= 12) TimePeriod.PM else TimePeriod.AM,
         timeFormat = TimeFormat.HOUR_12
     )
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BottomSheetSampleScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BottomSheetSampleScreen.kt
index 037b2fd..bb7ed63 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BottomSheetSampleScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BottomSheetSampleScreen.kt
@@ -36,7 +36,6 @@ import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
-import androidx.navigation.NavController
 import com.kez.picker.date.YearMonthPicker
 import com.kez.picker.rememberTimePickerState
 import com.kez.picker.rememberYearMonthPickerState
@@ -60,11 +59,13 @@ import kotlinx.datetime.number
 internal fun BottomSheetSampleScreen(
     onBackPressed: () -> Unit = {},
 ) {
-    // Date/time state management
+    val currentDate = currentDate()
     val yearMonthState = rememberYearMonthPickerState(
         initialYear = currentDate.year,
-        initialMonth = currentDate.monthNumber
+        initialMonth = currentDate.month.number
     )
+    val currentHour = currentHour()
+    val currentMinute = currentMinute()
     val timeState = rememberTimePickerState(
         initialHour = currentHour,
         initialMinute = currentMinute,
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/DatePickerSampleScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/DatePickerSampleScreen.kt
index bebd6e7..510fff3 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/DatePickerSampleScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/DatePickerSampleScreen.kt
@@ -3,15 +3,14 @@ package com.kez.picker.sample.ui.screen
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.ArrowBack
-import androidx.compose.material.icons.filled.DateRange
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
@@ -24,10 +23,15 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
-import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
 import com.kez.picker.date.DatePicker
 import com.kez.picker.rememberDatePickerState
+import compose.icons.FeatherIcons
+import compose.icons.feathericons.ArrowLeft
+import compose.icons.feathericons.Calendar
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -41,7 +45,7 @@ fun DatePickerSampleScreen(
                 navigationIcon = {
                     IconButton(onClick = onBackPressed) {
                         Icon(
-                            imageVector = Icons.Default.ArrowBack,
+                            imageVector = FeatherIcons.ArrowLeft,
                             contentDescription = "Back"
                         )
                     }
@@ -66,15 +70,16 @@ fun DatePickerSampleScreen(
                 modifier = Modifier
                     .fillMaxWidth()
                     .clip(RoundedCornerShape(16.dp))
-                    .background(MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.5f))
                     .padding(24.dp)
             ) {
                 DatePicker(
                     state = state,
                     visibleItemsCount = 3,
                     textStyle = MaterialTheme.typography.bodyLarge,
-                    selectedTextStyle = MaterialTheme.typography.headlineMedium.copy(
-                        color = MaterialTheme.colorScheme.primary
+                    selectedTextStyle = TextStyle(
+                        fontSize = 22.sp,
+                        color = MaterialTheme.colorScheme.primary,
+                        fontWeight = FontWeight.Bold
                     ),
                     dividerColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.5f)
                 )
@@ -98,13 +103,15 @@ fun DatePickerSampleScreen(
                     Spacer(modifier = Modifier.height(8.dp))
                     Row(verticalAlignment = Alignment.CenterVertically) {
                         Icon(
-                            imageVector = Icons.Default.DateRange,
+                            imageVector = FeatherIcons.Calendar,
                             contentDescription = null,
                             tint = MaterialTheme.colorScheme.onSecondaryContainer
                         )
                         Spacer(modifier = Modifier.width(8.dp))
                         Text(
-                            text = "${state.selectedYear}-${state.selectedMonth.toString().padStart(2, '0')}-${state.selectedDay.toString().padStart(2, '0')}",
+                            text = "${state.selectedYear}-${
+                                state.selectedMonth.toString().padStart(2, '0')
+                            }-${state.selectedDay.toString().padStart(2, '0')}",
                             style = MaterialTheme.typography.headlineSmall,
                             color = MaterialTheme.colorScheme.onSecondaryContainer
                         )
@@ -114,7 +121,3 @@ fun DatePickerSampleScreen(
         }
     }
 }
-
-// Helper imports that might be missing
-import androidx.compose.foundation.layout.Row
-import androidx.compose.foundation.layout.width
\ No newline at end of file
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/IntegratedPickerScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/IntegratedPickerScreen.kt
index dfda8f7..409c585 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/IntegratedPickerScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/IntegratedPickerScreen.kt
@@ -71,6 +71,10 @@ import kotlinx.datetime.number
 internal fun IntegratedPickerScreen(
     onBackPressed: () -> Unit = {},
 ) {
+    val currentDate = currentDate()
+    val currentHour = currentHour()
+    val currentMinute = currentMinute()
+
     val yearMonthState = rememberYearMonthPickerState(
         initialYear = currentDate.year,
         initialMonth = currentDate.month.number
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/YearMonthPickerSampleScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/YearMonthPickerSampleScreen.kt
index cda0198..f3394c1 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/YearMonthPickerSampleScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/YearMonthPickerSampleScreen.kt
@@ -28,7 +28,6 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.text.font.FontWeight
-import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import com.kez.picker.date.YearMonthPicker
@@ -45,6 +44,7 @@ import kotlinx.datetime.number
 internal fun YearMonthPickerSampleScreen(
     onBackPressed: () -> Unit = {},
 ) {
+    val currentDate = currentDate()
     val state = rememberYearMonthPickerState(
         initialYear = currentDate.year,
         initialMonth = currentDate.month.number
@@ -114,7 +114,7 @@ internal fun YearMonthPickerSampleScreen(
                 modifier = Modifier.padding(horizontal = 12.dp),
                 state = state
             )
-            
+
             Spacer(modifier = Modifier.height(16.dp))
         }
     }

From 6406e7539e9113ffa6ba03683a5b971beceae6ae Mon Sep 17 00:00:00 2001
From: Kez <kejprogramer0909@gmail.com>
Date: Sun, 14 Dec 2025 16:57:44 +0900
Subject: [PATCH 6/9] feat: Refactor DatePicker and Picker components to use
 default styles and improve code consistency

---
 .../kotlin/com/kez/picker/Picker.kt           | 109 +++++++-----------
 .../kotlin/com/kez/picker/PickerDefaults.kt   |  24 +++-
 .../kotlin/com/kez/picker/date/DatePicker.kt  | 101 +++++++---------
 .../com/kez/picker/date/YearMonthPicker.kt    |  71 +++++-------
 .../kotlin/com/kez/picker/time/TimePicker.kt  |  74 +++++-------
 5 files changed, 166 insertions(+), 213 deletions(-)

diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt
index c9c0738..9971a7c 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt
@@ -12,10 +12,7 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.wrapContentSize
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.rememberLazyListState
-import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.HorizontalDivider
-import androidx.compose.material3.LocalContentColor
-import androidx.compose.material3.LocalTextStyle
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
@@ -29,7 +26,6 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.drawWithContent
 import androidx.compose.ui.graphics.BlendMode
 import androidx.compose.ui.graphics.Brush
-import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.CompositingStrategy
 import androidx.compose.ui.graphics.Shape
 import androidx.compose.ui.graphics.graphicsLayer
@@ -40,12 +36,10 @@ import androidx.compose.ui.semantics.contentDescription
 import androidx.compose.ui.semantics.role
 import androidx.compose.ui.semantics.selected
 import androidx.compose.ui.semantics.semantics
-import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.Dp
-import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.isSpecified
 import androidx.compose.ui.unit.lerp
 import androidx.compose.ui.unit.sp
@@ -63,16 +57,15 @@ private const val INFINITE_SCROLL_MULTIPLIER = 1000
 
 /**
  * A generic picker component that displays a list of items and allows the user to select one.
+ * Follows Material3 component design patterns.
  *
  * @param items The list of items to display.
- * @param modifier The modifier to be applied to the picker.
  * @param state The state of the picker.
+ * @param modifier The modifier to be applied to the picker.
  * @param startIndex The initial index to display.
- * @param visibleItemsCount The number of items visible at once.
- * @param textStyle The style of the text for unselected items.
- * @param selectedTextStyle The style of the text for the selected item.
- * @param dividerColor The color of the dividers.
- * @param selectedItemBackgroundColor The background color of the selected item area.
+ * @param visibleItemsCount The number of items visible at once. Must be a positive odd number.
+ * @param colors The colors used by the picker. See [PickerDefaults.colors].
+ * @param textStyles The text styles used by the picker. See [PickerDefaults.textStyles].
  * @param selectedItemBackgroundShape The shape of the background of the selected item area.
  * @param itemPadding The padding around each item.
  * @param fadingEdgeGradient The gradient to use for fading edges.
@@ -82,6 +75,7 @@ private const val INFINITE_SCROLL_MULTIPLIER = 1000
  * @param dividerShape The shape of the dividers.
  * @param isDividerVisible Whether the divider should be visible.
  * @param isInfinity Whether the picker should loop infinitely.
+ * @param content Optional custom content composable for rendering each item.
  */
 @Composable
 fun <T> Picker(
@@ -89,22 +83,16 @@ fun <T> Picker(
     state: PickerState<T>,
     modifier: Modifier = Modifier,
     startIndex: Int = 0,
-    visibleItemsCount: Int = 3,
-    textStyle: TextStyle = LocalTextStyle.current,
-    selectedTextStyle: TextStyle = LocalTextStyle.current,
-    dividerColor: Color = LocalContentColor.current,
-    selectedItemBackgroundColor: Color = Color.Transparent,
-    selectedItemBackgroundShape: Shape = RoundedCornerShape(12.dp),
-    itemPadding: PaddingValues = PaddingValues(8.dp),
-    fadingEdgeGradient: Brush = Brush.verticalGradient(
-        0f to Color.Transparent,
-        0.5f to Color.Black,
-        1f to Color.Transparent
-    ),
+    visibleItemsCount: Int = PickerDefaults.VisibleItemsCount,
+    colors: PickerColors = PickerDefaults.colors(),
+    textStyles: PickerTextStyles = PickerDefaults.textStyles(),
+    selectedItemBackgroundShape: Shape = PickerDefaults.SelectedItemBackgroundShape,
+    itemPadding: PaddingValues = PickerDefaults.ItemPadding,
+    fadingEdgeGradient: Brush = PickerDefaults.fadingEdgeGradient(),
     horizontalAlignment: Alignment.Horizontal = Alignment.CenterHorizontally,
     itemTextAlignment: Alignment.Vertical = Alignment.CenterVertically,
-    dividerThickness: Dp = 1.dp,
-    dividerShape: Shape = RoundedCornerShape(10.dp),
+    dividerThickness: Dp = PickerDefaults.DividerThickness,
+    dividerShape: Shape = PickerDefaults.DividerShape,
     isDividerVisible: Boolean = true,
     isInfinity: Boolean = true,
     content: @Composable ((T) -> Unit)? = null
@@ -148,6 +136,9 @@ fun <T> Picker(
     val listState = rememberLazyListState(initialFirstVisibleItemIndex = listStartIndex)
     val flingBehavior = rememberSnapFlingBehavior(lazyListState = listState)
 
+    val textStyle = textStyles.textStyle
+    val selectedTextStyle = textStyles.selectedTextStyle
+
     val selectedLineHeight = selectedTextStyle.lineHeight.takeIf { it.isSpecified } ?: 0.sp
     val unselectedLineHeight = textStyle.lineHeight.takeIf { it.isSpecified } ?: 0.sp
     val largestLineHeight =
@@ -165,6 +156,7 @@ fun <T> Picker(
                 itemPadding.calculateTopPadding() +
                 itemPadding.calculateBottomPadding()
     }
+
     LaunchedEffect(listState) {
         snapshotFlow { listState.firstVisibleItemIndex }
             .mapNotNull { index -> getItem(index + visibleItemsMiddle) }
@@ -177,7 +169,7 @@ fun <T> Picker(
             modifier = Modifier
                 .align(Alignment.Center)
                 .background(
-                    color = selectedItemBackgroundColor,
+                    color = colors.selectedItemBackgroundColor,
                     shape = selectedItemBackgroundShape
                 )
                 .fillMaxWidth()
@@ -185,24 +177,24 @@ fun <T> Picker(
         ) {
             if (isDividerVisible) {
                 HorizontalDivider(
-                    color = dividerColor,
+                    color = colors.dividerColor,
                     thickness = dividerThickness,
                     modifier = Modifier
                         .fillMaxWidth()
                         .background(
-                            color = dividerColor,
+                            color = colors.dividerColor,
                             shape = dividerShape
                         )
                         .align(Alignment.TopCenter)
                 )
 
                 HorizontalDivider(
-                    color = dividerColor,
+                    color = colors.dividerColor,
                     thickness = dividerThickness,
                     modifier = Modifier
                         .fillMaxWidth()
                         .background(
-                            color = dividerColor,
+                            color = colors.dividerColor,
                             shape = dividerShape
                         )
                         .align(Alignment.BottomCenter)
@@ -278,13 +270,6 @@ fun <T> Picker(
                         if (content != null) {
                             content(item)
                         } else {
-                            val baseColor = LocalContentColor.current
-                            val selectedColor =
-                                if (selectedTextStyle.color == Color.Unspecified) baseColor else selectedTextStyle.color
-
-                            val normalColor =
-                                if (textStyle.color == Color.Unspecified) baseColor.copy(alpha = 0.7f) else textStyle.color
-
                             Text(
                                 text = itemDescription,
                                 maxLines = 1,
@@ -296,8 +281,8 @@ fun <T> Picker(
                                         fraction
                                     ),
                                     color = lerp(
-                                        start = selectedColor,
-                                        stop = normalColor,
+                                        start = colors.selectedTextColor,
+                                        stop = colors.textColor,
                                         fraction = fraction
                                     ),
                                 ),
@@ -330,9 +315,7 @@ fun PickerPreview() {
     val state = rememberPickerState("Item 1")
     Picker(
         items = listOf("1", "2", "3"),
-        state = state,
-        textStyle = TextStyle(fontSize = 16.sp),
-        selectedTextStyle = TextStyle(fontSize = 24.sp)
+        state = state
     )
 }
 
@@ -342,9 +325,7 @@ fun PickerLongTextPreview() {
     val state = rememberPickerState("Long Item 1")
     Picker(
         items = listOf("Long Item 1", "Long Item 2", "Long Item 3"),
-        state = state,
-        textStyle = TextStyle(fontSize = 16.sp),
-        selectedTextStyle = TextStyle(fontSize = 24.sp)
+        state = state
     )
 }
 
@@ -356,9 +337,7 @@ fun PickerManyItemsPreview() {
     Picker(
         items = items,
         state = state,
-        startIndex = 49,
-        textStyle = TextStyle(fontSize = 16.sp),
-        selectedTextStyle = TextStyle(fontSize = 24.sp)
+        startIndex = 49
     )
 }
 
@@ -369,9 +348,7 @@ fun PickerNoDividerPreview() {
     Picker(
         items = listOf("Item 1", "Item 2", "Item 3"),
         state = state,
-        isDividerVisible = false,
-        textStyle = TextStyle(fontSize = 16.sp),
-        selectedTextStyle = TextStyle(fontSize = 24.sp)
+        isDividerVisible = false
     )
 }
 
@@ -382,9 +359,11 @@ fun PickerCustomColorsPreview() {
     Picker(
         items = listOf("Red", "Green", "Blue"),
         state = state,
-        textStyle = TextStyle(fontSize = 16.sp, color = Color.Gray),
-        selectedTextStyle = TextStyle(fontSize = 24.sp, color = Color.Blue),
-        dividerColor = Color.Blue
+        colors = PickerDefaults.colors(
+            dividerColor = androidx.compose.ui.graphics.Color.Blue,
+            selectedTextColor = androidx.compose.ui.graphics.Color.Blue,
+            textColor = androidx.compose.ui.graphics.Color.Gray
+        )
     )
 }
 
@@ -395,9 +374,7 @@ fun PickerBoundedPreview() {
     Picker(
         items = listOf("Item 1", "Item 2", "Item 3", "Item 4", "Item 5"),
         state = state,
-        isInfinity = false,
-        textStyle = TextStyle(fontSize = 16.sp),
-        selectedTextStyle = TextStyle(fontSize = 24.sp)
+        isInfinity = false
     )
 }
 
@@ -410,9 +387,7 @@ fun Picker5VisibleItemsPreview() {
         items = items,
         state = state,
         startIndex = 4,
-        visibleItemsCount = 5,
-        textStyle = TextStyle(fontSize = 16.sp),
-        selectedTextStyle = TextStyle(fontSize = 24.sp)
+        visibleItemsCount = 5
     )
 }
 
@@ -423,9 +398,11 @@ fun PickerSelectedBackgroundPreview() {
     Picker(
         items = listOf("Item 1", "Item 2", "Item 3"),
         state = state,
-        textStyle = TextStyle(fontSize = 16.sp, color = Color.Gray),
-        selectedTextStyle = TextStyle(fontSize = 24.sp, color = Color.Blue),
-        dividerColor = Color.Blue,
-        selectedItemBackgroundColor = Color.Blue.copy(alpha = 0.1f)
+        colors = PickerDefaults.colors(
+            dividerColor = androidx.compose.ui.graphics.Color.Blue,
+            selectedTextColor = androidx.compose.ui.graphics.Color.Blue,
+            textColor = androidx.compose.ui.graphics.Color.Gray,
+            selectedItemBackgroundColor = androidx.compose.ui.graphics.Color.Blue.copy(alpha = 0.1f)
+        )
     )
-}
\ No newline at end of file
+}
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/PickerDefaults.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/PickerDefaults.kt
index 68742d9..c4fdde8 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/PickerDefaults.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/PickerDefaults.kt
@@ -16,11 +16,13 @@ import androidx.compose.ui.unit.sp
 
 /**
  * Contains default values and factory methods for creating Picker styles.
+ * Follows Material3 component design patterns.
  */
 object PickerDefaults {
 
     /**
      * Default number of visible items in the picker.
+     * Must be an odd number for proper center alignment.
      */
     const val VisibleItemsCount: Int = 3
 
@@ -35,9 +37,9 @@ object PickerDefaults {
     val DividerThickness: Dp = 1.dp
 
     /**
-     * Default spacing between pickers in composite components (e.g., TimePicker).
+     * Default spacing between pickers in composite components (e.g., TimePicker, DatePicker).
      */
-    val SpacingBetweenPickers: Dp = 20.dp
+    val SpacingBetweenPickers: Dp = 0.dp
 
     /**
      * Default shape for the selected item background.
@@ -54,15 +56,21 @@ object PickerDefaults {
      *
      * @param dividerColor The color of the dividers.
      * @param selectedItemBackgroundColor The background color of the selected item area.
+     * @param textColor The color of unselected item text.
+     * @param selectedTextColor The color of the selected item text.
      * @return A [PickerColors] instance with the specified colors.
      */
     @Composable
     fun colors(
         dividerColor: Color = LocalContentColor.current,
-        selectedItemBackgroundColor: Color = Color.Transparent
+        selectedItemBackgroundColor: Color = Color.Transparent,
+        textColor: Color = LocalContentColor.current.copy(alpha = 0.7f),
+        selectedTextColor: Color = LocalContentColor.current
     ): PickerColors = PickerColors(
         dividerColor = dividerColor,
-        selectedItemBackgroundColor = selectedItemBackgroundColor
+        selectedItemBackgroundColor = selectedItemBackgroundColor,
+        textColor = textColor,
+        selectedTextColor = selectedTextColor
     )
 
     /**
@@ -98,11 +106,16 @@ object PickerDefaults {
  *
  * @param dividerColor The color of the dividers.
  * @param selectedItemBackgroundColor The background color of the selected item area.
+ * @param textColor The color of unselected item text.
+ * @param selectedTextColor The color of the selected item text.
+ * @see PickerDefaults.colors
  */
 @Immutable
 data class PickerColors(
     val dividerColor: Color,
-    val selectedItemBackgroundColor: Color
+    val selectedItemBackgroundColor: Color,
+    val textColor: Color,
+    val selectedTextColor: Color
 )
 
 /**
@@ -110,6 +123,7 @@ data class PickerColors(
  *
  * @param textStyle The style of the text for unselected items.
  * @param selectedTextStyle The style of the text for the selected item.
+ * @see PickerDefaults.textStyles
  */
 @Immutable
 data class PickerTextStyles(
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
index 7f8ae06..f481c5b 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
@@ -6,29 +6,25 @@ import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material3.LocalContentColor
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
-import androidx.compose.runtime.key
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Brush
-import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.Shape
-import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.Dp
-import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.sp
-import com.kez.picker.Picker
 import com.kez.picker.DatePickerState
+import com.kez.picker.Picker
+import com.kez.picker.PickerColors
+import com.kez.picker.PickerDefaults
+import com.kez.picker.PickerTextStyles
 import com.kez.picker.rememberDatePickerState
 import com.kez.picker.util.MONTH_RANGE
 import com.kez.picker.util.YEAR_RANGE
 import com.kez.picker.util.currentDate
-import kotlinx.datetime.number
+import kotlinx.datetime.LocalDate
 
 /**
  * A date picker component that allows selecting year, month, and day.
@@ -40,12 +36,10 @@ import kotlinx.datetime.number
  * @param yearItems The list of year values to display.
  * @param monthItems The list of month values to display.
  * @param visibleItemsCount The number of items visible at once.
- * @param itemPadding The padding around each item.
- * @param textStyle The style of the text for unselected items.
- * @param selectedTextStyle The style of the text for the selected item.
- * @param dividerColor The color of the dividers.
- * @param selectedItemBackgroundColor The background color of the selected item area.
+ * @param colors The colors used by the picker. See [PickerDefaults.colors].
+ * @param textStyles The text styles used by the picker. See [PickerDefaults.textStyles].
  * @param selectedItemBackgroundShape The shape of the selected item background.
+ * @param itemPadding The padding around each item.
  * @param fadingEdgeGradient The gradient to use for fading edges.
  * @param horizontalAlignment The horizontal alignment of items.
  * @param verticalAlignment The vertical alignment of the text within items.
@@ -59,26 +53,20 @@ fun DatePicker(
     modifier: Modifier = Modifier,
     pickerModifier: Modifier = Modifier,
     state: DatePickerState = rememberDatePickerState(),
-    startLocalDate: kotlinx.datetime.LocalDate = currentDate(),
+    startLocalDate: LocalDate = currentDate(),
     yearItems: List<Int> = YEAR_RANGE,
     monthItems: List<Int> = MONTH_RANGE,
-    visibleItemsCount: Int = 3,
-    itemPadding: PaddingValues = PaddingValues(8.dp),
-    textStyle: TextStyle = TextStyle(fontSize = 16.sp),
-    selectedTextStyle: TextStyle = TextStyle(fontSize = 24.sp),
-    dividerColor: Color = LocalContentColor.current,
-    selectedItemBackgroundColor: Color = Color.Transparent,
-    selectedItemBackgroundShape: Shape = RoundedCornerShape(12.dp),
-    fadingEdgeGradient: Brush = Brush.verticalGradient(
-        0f to Color.Transparent,
-        0.5f to Color.Black,
-        1f to Color.Transparent
-    ),
+    visibleItemsCount: Int = PickerDefaults.VisibleItemsCount,
+    colors: PickerColors = PickerDefaults.colors(),
+    textStyles: PickerTextStyles = PickerDefaults.textStyles(),
+    selectedItemBackgroundShape: Shape = PickerDefaults.SelectedItemBackgroundShape,
+    itemPadding: PaddingValues = PickerDefaults.ItemPadding,
+    fadingEdgeGradient: Brush = PickerDefaults.fadingEdgeGradient(),
     horizontalAlignment: Alignment.Horizontal = Alignment.CenterHorizontally,
     verticalAlignment: Alignment.Vertical = Alignment.CenterVertically,
-    dividerThickness: Dp = 1.dp,
-    dividerShape: Shape = RoundedCornerShape(10.dp),
-    spacingBetweenPickers: Dp = 20.dp,
+    dividerThickness: Dp = PickerDefaults.DividerThickness,
+    dividerShape: Shape = PickerDefaults.DividerShape,
+    spacingBetweenPickers: Dp = PickerDefaults.SpacingBetweenPickers,
     isDividerVisible: Boolean = true
 ) {
     // Validate state whenever year or month changes to ensure day is within range
@@ -125,10 +113,8 @@ fun DatePicker(
                     items = yearItems,
                     startIndex = yearStartIndex,
                     visibleItemsCount = visibleItemsCount,
-                    textStyle = textStyle,
-                    selectedTextStyle = selectedTextStyle,
-                    dividerColor = dividerColor,
-                    selectedItemBackgroundColor = selectedItemBackgroundColor,
+                    colors = colors,
+                    textStyles = textStyles,
                     selectedItemBackgroundShape = selectedItemBackgroundShape,
                     itemPadding = itemPadding,
                     fadingEdgeGradient = fadingEdgeGradient,
@@ -138,7 +124,7 @@ fun DatePicker(
                     dividerShape = dividerShape,
                     isDividerVisible = isDividerVisible,
                 )
-                
+
                 // Month Picker
                 Picker(
                     state = state.monthState,
@@ -146,10 +132,8 @@ fun DatePicker(
                     startIndex = monthStartIndex,
                     visibleItemsCount = visibleItemsCount,
                     modifier = pickerModifier.weight(0.8f),
-                    textStyle = textStyle,
-                    selectedTextStyle = selectedTextStyle,
-                    dividerColor = dividerColor,
-                    selectedItemBackgroundColor = selectedItemBackgroundColor,
+                    colors = colors,
+                    textStyles = textStyles,
                     selectedItemBackgroundShape = selectedItemBackgroundShape,
                     itemPadding = itemPadding,
                     fadingEdgeGradient = fadingEdgeGradient,
@@ -161,27 +145,24 @@ fun DatePicker(
                 )
 
                 // Day Picker
-                key(maxDay) {
-                    Picker(
-                        state = state.dayState,
-                        items = dayItems,
-                        startIndex = dayStartIndex,
-                        visibleItemsCount = visibleItemsCount,
-                        modifier = pickerModifier.weight(0.8f),
-                        textStyle = textStyle,
-                        selectedTextStyle = selectedTextStyle,
-                        dividerColor = dividerColor,
-                        selectedItemBackgroundColor = selectedItemBackgroundColor,
-                        selectedItemBackgroundShape = selectedItemBackgroundShape,
-                        itemPadding = itemPadding,
-                        fadingEdgeGradient = fadingEdgeGradient,
-                        horizontalAlignment = horizontalAlignment,
-                        itemTextAlignment = verticalAlignment,
-                        dividerThickness = dividerThickness,
-                        dividerShape = dividerShape,
-                        isDividerVisible = isDividerVisible,
-                    )
-                }
+                Picker(
+                    state = state.dayState,
+                    items = dayItems,
+                    startIndex = dayStartIndex,
+                    visibleItemsCount = visibleItemsCount,
+                    modifier = pickerModifier.weight(0.8f),
+                    colors = colors,
+                    textStyles = textStyles,
+                    selectedItemBackgroundShape = selectedItemBackgroundShape,
+                    itemPadding = itemPadding,
+                    isInfinity = false,
+                    fadingEdgeGradient = fadingEdgeGradient,
+                    horizontalAlignment = horizontalAlignment,
+                    itemTextAlignment = verticalAlignment,
+                    dividerThickness = dividerThickness,
+                    dividerShape = dividerShape,
+                    isDividerVisible = isDividerVisible,
+                )
             }
         }
     }
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt
index 4c94757..41caab7 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt
@@ -6,8 +6,6 @@ import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material3.LocalContentColor
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
@@ -15,17 +13,19 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.Shape
-import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.Dp
-import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import com.kez.picker.Picker
+import com.kez.picker.PickerColors
+import com.kez.picker.PickerDefaults
+import com.kez.picker.PickerTextStyles
 import com.kez.picker.YearMonthPickerState
 import com.kez.picker.rememberYearMonthPickerState
 import com.kez.picker.util.MONTH_RANGE
 import com.kez.picker.util.YEAR_RANGE
 import com.kez.picker.util.currentDate
+import kotlinx.datetime.LocalDate
 import kotlinx.datetime.number
 
 /**
@@ -33,18 +33,15 @@ import kotlinx.datetime.number
  *
  * @param modifier The modifier to be applied to the component.
  * @param pickerModifier The modifier to be applied to each picker.
- * @param yearPickerState The state for the year picker.
- * @param monthPickerState The state for the month picker.
+ * @param state The state object to control the picker.
  * @param startLocalDate The initial date to display.
  * @param yearItems The list of year values to display.
  * @param monthItems The list of month values to display.
  * @param visibleItemsCount The number of items visible at once.
- * @param itemPadding The padding around each item.
- * @param textStyle The style of the text for unselected items.
- * @param selectedTextStyle The style of the text for the selected item.
- * @param dividerColor The color of the dividers.
- * @param selectedItemBackgroundColor The background color of each individual picker's selected item area.
+ * @param colors The colors used by the picker. See [PickerDefaults.colors].
+ * @param textStyles The text styles used by the picker. See [PickerDefaults.textStyles].
  * @param selectedItemBackgroundShape The shape of the selected item background.
+ * @param itemPadding The padding around each item.
  * @param fadingEdgeGradient The gradient to use for fading edges.
  * @param horizontalAlignment The horizontal alignment of items.
  * @param verticalAlignment The vertical alignment of the text within items.
@@ -58,26 +55,20 @@ fun YearMonthPicker(
     modifier: Modifier = Modifier,
     pickerModifier: Modifier = Modifier,
     state: YearMonthPickerState = rememberYearMonthPickerState(),
-    startLocalDate: kotlinx.datetime.LocalDate = currentDate(),
+    startLocalDate: LocalDate = currentDate(),
     yearItems: List<Int> = YEAR_RANGE,
     monthItems: List<Int> = MONTH_RANGE,
-    visibleItemsCount: Int = 3,
-    itemPadding: PaddingValues = PaddingValues(8.dp),
-    textStyle: TextStyle = TextStyle(fontSize = 16.sp),
-    selectedTextStyle: TextStyle = TextStyle(fontSize = 24.sp),
-    dividerColor: Color = LocalContentColor.current,
-    selectedItemBackgroundColor: Color = Color.Transparent,
-    selectedItemBackgroundShape: Shape = RoundedCornerShape(12.dp),
-    fadingEdgeGradient: Brush = Brush.verticalGradient(
-        0f to Color.Transparent,
-        0.5f to Color.Black,
-        1f to Color.Transparent
-    ),
+    visibleItemsCount: Int = PickerDefaults.VisibleItemsCount,
+    colors: PickerColors = PickerDefaults.colors(),
+    textStyles: PickerTextStyles = PickerDefaults.textStyles(),
+    selectedItemBackgroundShape: Shape = PickerDefaults.SelectedItemBackgroundShape,
+    itemPadding: PaddingValues = PickerDefaults.ItemPadding,
+    fadingEdgeGradient: Brush = PickerDefaults.fadingEdgeGradient(),
     horizontalAlignment: Alignment.Horizontal = Alignment.CenterHorizontally,
     verticalAlignment: Alignment.Vertical = Alignment.CenterVertically,
-    dividerThickness: Dp = 2.dp,
-    dividerShape: Shape = RoundedCornerShape(10.dp),
-    spacingBetweenPickers: Dp = 20.dp,
+    dividerThickness: Dp = PickerDefaults.DividerThickness,
+    dividerShape: Shape = PickerDefaults.DividerShape,
+    spacingBetweenPickers: Dp = PickerDefaults.SpacingBetweenPickers,
     isDividerVisible: Boolean = true
 ) {
     Box(modifier = modifier) {
@@ -107,10 +98,8 @@ fun YearMonthPicker(
                     items = yearItems,
                     startIndex = yearStartIndex,
                     visibleItemsCount = visibleItemsCount,
-                    textStyle = textStyle,
-                    selectedTextStyle = selectedTextStyle,
-                    dividerColor = dividerColor,
-                    selectedItemBackgroundColor = selectedItemBackgroundColor,
+                    colors = colors,
+                    textStyles = textStyles,
                     selectedItemBackgroundShape = selectedItemBackgroundShape,
                     itemPadding = itemPadding,
                     fadingEdgeGradient = fadingEdgeGradient,
@@ -126,10 +115,8 @@ fun YearMonthPicker(
                     startIndex = monthStartIndex,
                     visibleItemsCount = visibleItemsCount,
                     modifier = pickerModifier.weight(1f),
-                    textStyle = textStyle,
-                    selectedTextStyle = selectedTextStyle,
-                    dividerColor = dividerColor,
-                    selectedItemBackgroundColor = selectedItemBackgroundColor,
+                    colors = colors,
+                    textStyles = textStyles,
                     selectedItemBackgroundShape = selectedItemBackgroundShape,
                     itemPadding = itemPadding,
                     fadingEdgeGradient = fadingEdgeGradient,
@@ -162,9 +149,11 @@ fun YearMonthPickerNoDividerPreview() {
 @Composable
 fun YearMonthPickerCustomColorsPreview() {
     YearMonthPicker(
-        textStyle = TextStyle(fontSize = 16.sp, color = Color.Gray),
-        selectedTextStyle = TextStyle(fontSize = 24.sp, color = Color(0xFF03DAC5)),
-        dividerColor = Color(0xFF03DAC5)
+        colors = PickerDefaults.colors(
+            textColor = Color.Gray,
+            selectedTextColor = Color(0xFF03DAC5),
+            dividerColor = Color(0xFF03DAC5)
+        )
     )
 }
 
@@ -172,8 +161,10 @@ fun YearMonthPickerCustomColorsPreview() {
 @Composable
 fun YearMonthPickerLargeTextPreview() {
     YearMonthPicker(
-        textStyle = TextStyle(fontSize = 18.sp),
-        selectedTextStyle = TextStyle(fontSize = 28.sp),
+        textStyles = PickerDefaults.textStyles(
+            textStyle = androidx.compose.ui.text.TextStyle(fontSize = 18.sp),
+            selectedTextStyle = androidx.compose.ui.text.TextStyle(fontSize = 28.sp)
+        ),
         visibleItemsCount = 5
     )
 }
\ No newline at end of file
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt
index 2a0b885..e5e4fa4 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt
@@ -8,8 +8,6 @@ import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.width
-import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material3.LocalContentColor
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
@@ -17,12 +15,13 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.Shape
-import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.Dp
-import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import com.kez.picker.Picker
+import com.kez.picker.PickerColors
+import com.kez.picker.PickerDefaults
+import com.kez.picker.PickerTextStyles
 import com.kez.picker.TimePickerState
 import com.kez.picker.rememberTimePickerState
 import com.kez.picker.util.HOUR12_RANGE
@@ -31,6 +30,7 @@ import com.kez.picker.util.MINUTE_RANGE
 import com.kez.picker.util.TimeFormat
 import com.kez.picker.util.TimePeriod
 import com.kez.picker.util.currentDateTime
+import kotlinx.datetime.LocalDateTime
 
 /**
  * A time picker component that allows the user to select hours, minutes, and—when using the 12-hour format—the AM/PM period.
@@ -43,12 +43,10 @@ import com.kez.picker.util.currentDateTime
  * @param hourItems The list of hour values to display.
  * @param periodItems The list of period values to display.
  * @param visibleItemsCount The number of items visible at once.
- * @param itemPadding The padding around each item.
- * @param textStyle The style of the text for unselected items.
- * @param selectedTextStyle The style of the text for the selected item.
- * @param dividerColor The color of the dividers.
- * @param selectedItemBackgroundColor The background color of the selected item area.
+ * @param colors The colors used by the picker. See [PickerDefaults.colors].
+ * @param textStyles The text styles used by the picker. See [PickerDefaults.textStyles].
  * @param selectedItemBackgroundShape The shape of the selected item background.
+ * @param itemPadding The padding around each item.
  * @param fadingEdgeGradient The gradient to use for fading edges.
  * @param horizontalAlignment The horizontal alignment of items.
  * @param verticalAlignment The vertical alignment of the text within items.
@@ -62,30 +60,24 @@ fun TimePicker(
     modifier: Modifier = Modifier,
     pickerModifier: Modifier = Modifier,
     state: TimePickerState = rememberTimePickerState(),
-    startTime: kotlinx.datetime.LocalDateTime = currentDateTime(),
+    startTime: LocalDateTime = currentDateTime(),
     minuteItems: List<Int> = MINUTE_RANGE,
     hourItems: List<Int> = when (state.timeFormat) {
         TimeFormat.HOUR_12 -> HOUR12_RANGE
         TimeFormat.HOUR_24 -> HOUR24_RANGE
     },
     periodItems: List<TimePeriod> = TimePeriod.entries,
-    visibleItemsCount: Int = 3,
-    itemPadding: PaddingValues = PaddingValues(8.dp),
-    textStyle: TextStyle = TextStyle(fontSize = 16.sp),
-    selectedTextStyle: TextStyle = TextStyle(fontSize = 22.sp),
-    dividerColor: Color = LocalContentColor.current,
-    selectedItemBackgroundColor: Color = Color.Transparent,
-    selectedItemBackgroundShape: Shape = RoundedCornerShape(12.dp),
-    fadingEdgeGradient: Brush = Brush.verticalGradient(
-        0f to Color.Transparent,
-        0.5f to Color.Black,
-        1f to Color.Transparent
-    ),
+    visibleItemsCount: Int = PickerDefaults.VisibleItemsCount,
+    colors: PickerColors = PickerDefaults.colors(),
+    textStyles: PickerTextStyles = PickerDefaults.textStyles(),
+    selectedItemBackgroundShape: Shape = PickerDefaults.SelectedItemBackgroundShape,
+    itemPadding: PaddingValues = PickerDefaults.ItemPadding,
+    fadingEdgeGradient: Brush = PickerDefaults.fadingEdgeGradient(),
     horizontalAlignment: Alignment.Horizontal = Alignment.CenterHorizontally,
     verticalAlignment: Alignment.Vertical = Alignment.CenterVertically,
-    dividerThickness: Dp = 1.dp,
-    dividerShape: Shape = RoundedCornerShape(10.dp),
-    spacingBetweenPickers: Dp = 20.dp,
+    dividerThickness: Dp = PickerDefaults.DividerThickness,
+    dividerShape: Shape = PickerDefaults.DividerShape,
+    spacingBetweenPickers: Dp = PickerDefaults.SpacingBetweenPickers,
     isDividerVisible: Boolean = true
 ) {
     Box(modifier = modifier) {
@@ -127,10 +119,8 @@ fun TimePicker(
                         items = periodItems,
                         visibleItemsCount = visibleItemsCount,
                         modifier = pickerModifier.weight(1f),
-                        textStyle = textStyle,
-                        selectedTextStyle = selectedTextStyle,
-                        dividerColor = dividerColor,
-                        selectedItemBackgroundColor = selectedItemBackgroundColor,
+                        colors = colors,
+                        textStyles = textStyles,
                         selectedItemBackgroundShape = selectedItemBackgroundShape,
                         itemPadding = itemPadding,
                         startIndex = periodStartIndex,
@@ -150,10 +140,8 @@ fun TimePicker(
                     items = hourItems,
                     startIndex = hourStartIndex,
                     visibleItemsCount = visibleItemsCount,
-                    textStyle = textStyle,
-                    selectedTextStyle = selectedTextStyle,
-                    dividerColor = dividerColor,
-                    selectedItemBackgroundColor = selectedItemBackgroundColor,
+                    colors = colors,
+                    textStyles = textStyles,
                     selectedItemBackgroundShape = selectedItemBackgroundShape,
                     itemPadding = itemPadding,
                     fadingEdgeGradient = fadingEdgeGradient,
@@ -170,10 +158,8 @@ fun TimePicker(
                     startIndex = minuteStartIndex,
                     visibleItemsCount = visibleItemsCount,
                     modifier = pickerModifier.weight(1f),
-                    textStyle = textStyle,
-                    selectedTextStyle = selectedTextStyle,
-                    dividerColor = dividerColor,
-                    selectedItemBackgroundColor = selectedItemBackgroundColor,
+                    colors = colors,
+                    textStyles = textStyles,
                     selectedItemBackgroundShape = selectedItemBackgroundShape,
                     itemPadding = itemPadding,
                     fadingEdgeGradient = fadingEdgeGradient,
@@ -218,9 +204,11 @@ fun TimePickerNoDividerPreview() {
 fun TimePickerCustomColorsPreview() {
     TimePicker(
         state = rememberTimePickerState(timeFormat = TimeFormat.HOUR_12),
-        textStyle = TextStyle(fontSize = 16.sp, color = Color.Gray),
-        selectedTextStyle = TextStyle(fontSize = 22.sp, color = Color(0xFF6200EE)),
-        dividerColor = Color(0xFF6200EE)
+        colors = PickerDefaults.colors(
+            textColor = Color.Gray,
+            selectedTextColor = Color(0xFF6200EE),
+            dividerColor = Color(0xFF6200EE)
+        )
     )
 }
 
@@ -229,8 +217,10 @@ fun TimePickerCustomColorsPreview() {
 fun TimePickerLargeTextPreview() {
     TimePicker(
         state = rememberTimePickerState(timeFormat = TimeFormat.HOUR_24),
-        textStyle = TextStyle(fontSize = 20.sp),
-        selectedTextStyle = TextStyle(fontSize = 28.sp),
+        textStyles = PickerDefaults.textStyles(
+            textStyle = androidx.compose.ui.text.TextStyle(fontSize = 20.sp),
+            selectedTextStyle = androidx.compose.ui.text.TextStyle(fontSize = 28.sp)
+        ),
         visibleItemsCount = 5
     )
 }
\ No newline at end of file

From 1bbf0bbb152eee0141962bbecee758f2984482e4 Mon Sep 17 00:00:00 2001
From: Kez <kejprogramer0909@gmail.com>
Date: Fri, 2 Jan 2026 00:01:54 +0900
Subject: [PATCH 7/9] test: Add comprehensive unit tests for picker states and
 utilities
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- Add PickerStateTest with 6 tests for generic state management
- Add TimePickerStateTest with 12 tests covering 12/24-hour formats
- Add YearMonthPickerStateTest with 14 tests for year/month state
- Add PickerUtilsTest with 11 tests for utility calculations

Test coverage improved from 16 to 59 tests (+43 tests)
Supports 1.0.0 stability goals

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
---
 .../kotlin/com/kez/picker/PickerStateTest.kt  |  58 +++++
 .../kotlin/com/kez/picker/PickerUtilsTest.kt  | 143 ++++++++++++
 .../com/kez/picker/TimePickerStateTest.kt     | 203 ++++++++++++++++++
 .../kez/picker/YearMonthPickerStateTest.kt    | 193 +++++++++++++++++
 4 files changed, 597 insertions(+)
 create mode 100644 datetimepicker/src/commonTest/kotlin/com/kez/picker/PickerStateTest.kt
 create mode 100644 datetimepicker/src/commonTest/kotlin/com/kez/picker/PickerUtilsTest.kt
 create mode 100644 datetimepicker/src/commonTest/kotlin/com/kez/picker/TimePickerStateTest.kt
 create mode 100644 datetimepicker/src/commonTest/kotlin/com/kez/picker/YearMonthPickerStateTest.kt

diff --git a/datetimepicker/src/commonTest/kotlin/com/kez/picker/PickerStateTest.kt b/datetimepicker/src/commonTest/kotlin/com/kez/picker/PickerStateTest.kt
new file mode 100644
index 0000000..262362e
--- /dev/null
+++ b/datetimepicker/src/commonTest/kotlin/com/kez/picker/PickerStateTest.kt
@@ -0,0 +1,58 @@
+package com.kez.picker
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNotEquals
+
+/**
+ * Unit tests for [PickerState] class.
+ *
+ * Tests cover:
+ * - Initial value setting
+ * - State updates
+ * - Generic type support
+ */
+class PickerStateTest {
+
+    @Test
+    fun pickerState_initialValue_isCorrect() {
+        val state = PickerState("Initial")
+        assertEquals("Initial", state.selectedItem)
+    }
+
+    @Test
+    fun pickerState_intInitialValue_isCorrect() {
+        val state = PickerState(42)
+        assertEquals(42, state.selectedItem)
+    }
+
+    @Test
+    fun pickerState_nullableInitialValue_isCorrect() {
+        val state = PickerState<String?>(null)
+        assertEquals(null, state.selectedItem)
+    }
+
+    @Test
+    fun pickerState_customObjectInitialValue_isCorrect() {
+        data class CustomItem(val id: Int, val name: String)
+        val item = CustomItem(1, "Test")
+        val state = PickerState(item)
+        assertEquals(item, state.selectedItem)
+    }
+
+    @Test
+    fun pickerState_differentInstances_areIndependent() {
+        val state1 = PickerState("State1")
+        val state2 = PickerState("State2")
+
+        assertNotEquals(state1.selectedItem, state2.selectedItem)
+    }
+
+    @Test
+    fun pickerState_sameInitialValue_areEqual() {
+        val state1 = PickerState(100)
+        val state2 = PickerState(100)
+
+        assertEquals(state1.selectedItem, state2.selectedItem)
+    }
+}
diff --git a/datetimepicker/src/commonTest/kotlin/com/kez/picker/PickerUtilsTest.kt b/datetimepicker/src/commonTest/kotlin/com/kez/picker/PickerUtilsTest.kt
new file mode 100644
index 0000000..765276d
--- /dev/null
+++ b/datetimepicker/src/commonTest/kotlin/com/kez/picker/PickerUtilsTest.kt
@@ -0,0 +1,143 @@
+package com.kez.picker
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+/**
+ * Unit tests for Picker utility functions and calculations.
+ *
+ * Tests cover:
+ * - Index calculations for infinite scroll
+ * - Modulo operations for cyclic behavior
+ * - Edge case handling
+ */
+class PickerUtilsTest {
+
+    // ==================== Modulo Index Calculation Tests ====================
+
+    @Test
+    fun modIndex_positiveValues_calculatesCorrectly() {
+        val items = listOf("A", "B", "C")
+        val size = items.size
+
+        assertEquals(0, 0.mod(size))
+        assertEquals(1, 1.mod(size))
+        assertEquals(2, 2.mod(size))
+        assertEquals(0, 3.mod(size))
+        assertEquals(1, 4.mod(size))
+    }
+
+    @Test
+    fun modIndex_largeValues_calculatesCorrectly() {
+        val items = listOf(1, 2, 3, 4, 5)
+        val size = items.size
+
+        assertEquals(0, 1000.mod(size))
+        assertEquals(1, 1001.mod(size))
+        assertEquals(4, 999.mod(size))
+    }
+
+    @Test
+    fun modIndex_negativeValues_handledCorrectly() {
+        val size = 5
+
+        // Kotlin's mod() handles negative numbers correctly
+        assertEquals(4, (-1).mod(size))
+        assertEquals(3, (-2).mod(size))
+        assertEquals(0, (-5).mod(size))
+    }
+
+    // ==================== Visible Items Count Validation Tests ====================
+
+    @Test
+    fun visibleItemsCount_oddNumbers_areValid() {
+        val validCounts = listOf(1, 3, 5, 7, 9, 11)
+
+        for (count in validCounts) {
+            assertTrue(count > 0 && count % 2 == 1, "Count $count should be a positive odd number")
+        }
+    }
+
+    @Test
+    fun visibleItemsCount_evenNumbers_areInvalid() {
+        val invalidCounts = listOf(2, 4, 6, 8, 10)
+
+        for (count in invalidCounts) {
+            assertTrue(count % 2 == 0, "Count $count should be an even number")
+        }
+    }
+
+    // ==================== List Middle Calculation Tests ====================
+
+    @Test
+    fun listMiddle_calculatesCorrectly() {
+        assertEquals(0, 1 / 2)
+        assertEquals(1, 3 / 2)
+        assertEquals(2, 5 / 2)
+        assertEquals(3, 7 / 2)
+    }
+
+    // ==================== Infinite Scroll Multiplier Tests ====================
+
+    @Test
+    fun infiniteScrollMultiplier_producesReasonableSize() {
+        val items = listOf("A", "B", "C")
+        val multiplier = 1000
+        val listScrollCount = items.size * multiplier
+
+        assertEquals(3000, listScrollCount)
+        assertTrue(listScrollCount < Int.MAX_VALUE)
+    }
+
+    @Test
+    fun infiniteScrollMultiplier_centerCalculation_isCorrect() {
+        val items = listOf("A", "B", "C", "D", "E")
+        val multiplier = 1000
+        val listScrollCount = items.size * multiplier
+        val listScrollMiddle = listScrollCount / 2
+
+        assertEquals(2500, listScrollMiddle)
+    }
+
+    // ==================== Start Index Calculation Tests ====================
+
+    @Test
+    fun startIndex_infinityMode_calculatesCorrectly() {
+        val items = listOf("A", "B", "C", "D", "E")
+        val itemSize = items.size
+        val multiplier = 1000
+        val listScrollCount = itemSize * multiplier
+        val listScrollMiddle = listScrollCount / 2
+        val visibleItemsMiddle = 1 // for visibleItemsCount = 3
+        val startIndex = 2
+
+        val expectedStartIndex =
+            listScrollMiddle - listScrollMiddle % itemSize - visibleItemsMiddle + startIndex
+
+        // Should position us near the middle but at the correct item
+        assertTrue(expectedStartIndex > 0)
+        assertTrue(expectedStartIndex < listScrollCount)
+    }
+
+    @Test
+    fun startIndex_boundedMode_calculatesCorrectly() {
+        val startIndex = 2
+        val expectedBoundedStart = startIndex + 1 // +1 for null padding
+
+        assertEquals(3, expectedBoundedStart)
+    }
+
+    // ==================== Fraction Calculation Tests ====================
+
+    @Test
+    fun fraction_coerceInRange_worksCorrectly() {
+        val testValues = listOf(-2f, -1f, -0.5f, 0f, 0.5f, 1f, 2f)
+        val expectedResults = listOf(1f, 1f, 0.5f, 0f, 0.5f, 1f, 1f)
+
+        testValues.zip(expectedResults).forEach { (input, expected) ->
+            val result = kotlin.math.abs(input.coerceIn(-1f, 1f))
+            assertEquals(expected, result, 0.001f, "For input $input, expected $expected but got $result")
+        }
+    }
+}
diff --git a/datetimepicker/src/commonTest/kotlin/com/kez/picker/TimePickerStateTest.kt b/datetimepicker/src/commonTest/kotlin/com/kez/picker/TimePickerStateTest.kt
new file mode 100644
index 0000000..4716e7e
--- /dev/null
+++ b/datetimepicker/src/commonTest/kotlin/com/kez/picker/TimePickerStateTest.kt
@@ -0,0 +1,203 @@
+package com.kez.picker
+
+import com.kez.picker.util.TimeFormat
+import com.kez.picker.util.TimePeriod
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+/**
+ * Unit tests for [TimePickerState] class.
+ *
+ * Tests cover:
+ * - 24-hour format initialization
+ * - 12-hour format initialization with AM/PM
+ * - Boundary conditions for hours and minutes
+ * - Period (AM/PM) handling
+ */
+class TimePickerStateTest {
+
+    // ==================== 24-hour Format Tests ====================
+
+    @Test
+    fun timePickerState_24HourFormat_initialValues_areCorrect() {
+        val state = TimePickerState(
+            initialHour = 14,
+            initialMinute = 30,
+            initialPeriod = TimePeriod.PM,
+            timeFormat = TimeFormat.HOUR_24
+        )
+
+        assertEquals(14, state.selectedHour)
+        assertEquals(30, state.selectedMinute)
+        assertEquals(TimeFormat.HOUR_24, state.timeFormat)
+    }
+
+    @Test
+    fun timePickerState_24HourFormat_midnight_isCorrect() {
+        val state = TimePickerState(
+            initialHour = 0,
+            initialMinute = 0,
+            initialPeriod = TimePeriod.AM,
+            timeFormat = TimeFormat.HOUR_24
+        )
+
+        assertEquals(0, state.selectedHour)
+        assertEquals(0, state.selectedMinute)
+    }
+
+    @Test
+    fun timePickerState_24HourFormat_noon_isCorrect() {
+        val state = TimePickerState(
+            initialHour = 12,
+            initialMinute = 0,
+            initialPeriod = TimePeriod.PM,
+            timeFormat = TimeFormat.HOUR_24
+        )
+
+        assertEquals(12, state.selectedHour)
+        assertEquals(0, state.selectedMinute)
+    }
+
+    @Test
+    fun timePickerState_24HourFormat_endOfDay_isCorrect() {
+        val state = TimePickerState(
+            initialHour = 23,
+            initialMinute = 59,
+            initialPeriod = TimePeriod.PM,
+            timeFormat = TimeFormat.HOUR_24
+        )
+
+        assertEquals(23, state.selectedHour)
+        assertEquals(59, state.selectedMinute)
+    }
+
+    // ==================== 12-hour Format Tests ====================
+
+    @Test
+    fun timePickerState_12HourFormat_morning_isCorrect() {
+        val state = TimePickerState(
+            initialHour = 9,
+            initialMinute = 30,
+            initialPeriod = TimePeriod.AM,
+            timeFormat = TimeFormat.HOUR_12
+        )
+
+        assertEquals(9, state.selectedHour)
+        assertEquals(30, state.selectedMinute)
+        assertEquals(TimePeriod.AM, state.selectedPeriod)
+    }
+
+    @Test
+    fun timePickerState_12HourFormat_afternoon_isCorrect() {
+        val state = TimePickerState(
+            initialHour = 3,
+            initialMinute = 45,
+            initialPeriod = TimePeriod.PM,
+            timeFormat = TimeFormat.HOUR_12
+        )
+
+        assertEquals(3, state.selectedHour)
+        assertEquals(45, state.selectedMinute)
+        assertEquals(TimePeriod.PM, state.selectedPeriod)
+    }
+
+    @Test
+    fun timePickerState_12HourFormat_12AM_midnight_isCorrect() {
+        val state = TimePickerState(
+            initialHour = 12,
+            initialMinute = 0,
+            initialPeriod = TimePeriod.AM,
+            timeFormat = TimeFormat.HOUR_12
+        )
+
+        assertEquals(12, state.selectedHour)
+        assertEquals(0, state.selectedMinute)
+        assertEquals(TimePeriod.AM, state.selectedPeriod)
+    }
+
+    @Test
+    fun timePickerState_12HourFormat_12PM_noon_isCorrect() {
+        val state = TimePickerState(
+            initialHour = 12,
+            initialMinute = 0,
+            initialPeriod = TimePeriod.PM,
+            timeFormat = TimeFormat.HOUR_12
+        )
+
+        assertEquals(12, state.selectedHour)
+        assertEquals(0, state.selectedMinute)
+        assertEquals(TimePeriod.PM, state.selectedPeriod)
+    }
+
+    // ==================== Minute Boundary Tests ====================
+
+    @Test
+    fun timePickerState_minuteZero_isCorrect() {
+        val state = TimePickerState(
+            initialHour = 10,
+            initialMinute = 0,
+            initialPeriod = TimePeriod.AM,
+            timeFormat = TimeFormat.HOUR_24
+        )
+
+        assertEquals(0, state.selectedMinute)
+    }
+
+    @Test
+    fun timePickerState_minute59_isCorrect() {
+        val state = TimePickerState(
+            initialHour = 10,
+            initialMinute = 59,
+            initialPeriod = TimePeriod.AM,
+            timeFormat = TimeFormat.HOUR_24
+        )
+
+        assertEquals(59, state.selectedMinute)
+    }
+
+    // ==================== State Independence Tests ====================
+
+    @Test
+    fun timePickerState_multipleInstances_areIndependent() {
+        val state1 = TimePickerState(
+            initialHour = 10,
+            initialMinute = 30,
+            initialPeriod = TimePeriod.AM,
+            timeFormat = TimeFormat.HOUR_24
+        )
+
+        val state2 = TimePickerState(
+            initialHour = 15,
+            initialMinute = 45,
+            initialPeriod = TimePeriod.PM,
+            timeFormat = TimeFormat.HOUR_24
+        )
+
+        assertEquals(10, state1.selectedHour)
+        assertEquals(15, state2.selectedHour)
+        assertEquals(30, state1.selectedMinute)
+        assertEquals(45, state2.selectedMinute)
+    }
+
+    // ==================== TimeFormat Tests ====================
+
+    @Test
+    fun timePickerState_timeFormatProperty_isCorrect() {
+        val state24 = TimePickerState(
+            initialHour = 10,
+            initialMinute = 0,
+            initialPeriod = TimePeriod.AM,
+            timeFormat = TimeFormat.HOUR_24
+        )
+
+        val state12 = TimePickerState(
+            initialHour = 10,
+            initialMinute = 0,
+            initialPeriod = TimePeriod.AM,
+            timeFormat = TimeFormat.HOUR_12
+        )
+
+        assertEquals(TimeFormat.HOUR_24, state24.timeFormat)
+        assertEquals(TimeFormat.HOUR_12, state12.timeFormat)
+    }
+}
diff --git a/datetimepicker/src/commonTest/kotlin/com/kez/picker/YearMonthPickerStateTest.kt b/datetimepicker/src/commonTest/kotlin/com/kez/picker/YearMonthPickerStateTest.kt
new file mode 100644
index 0000000..1b7a3d3
--- /dev/null
+++ b/datetimepicker/src/commonTest/kotlin/com/kez/picker/YearMonthPickerStateTest.kt
@@ -0,0 +1,193 @@
+package com.kez.picker
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNotEquals
+
+/**
+ * Unit tests for [YearMonthPickerState] class.
+ *
+ * Tests cover:
+ * - Initial value setting for year and month
+ * - Boundary conditions for months (1-12)
+ * - Various year values
+ * - State independence
+ */
+class YearMonthPickerStateTest {
+
+    // ==================== Initial Value Tests ====================
+
+    @Test
+    fun yearMonthPickerState_initialValues_areCorrect() {
+        val state = YearMonthPickerState(
+            initialYear = 2024,
+            initialMonth = 6
+        )
+
+        assertEquals(2024, state.selectedYear)
+        assertEquals(6, state.selectedMonth)
+    }
+
+    @Test
+    fun yearMonthPickerState_januaryFirstMonth_isCorrect() {
+        val state = YearMonthPickerState(
+            initialYear = 2024,
+            initialMonth = 1
+        )
+
+        assertEquals(1, state.selectedMonth)
+    }
+
+    @Test
+    fun yearMonthPickerState_decemberLastMonth_isCorrect() {
+        val state = YearMonthPickerState(
+            initialYear = 2024,
+            initialMonth = 12
+        )
+
+        assertEquals(12, state.selectedMonth)
+    }
+
+    // ==================== Year Boundary Tests ====================
+
+    @Test
+    fun yearMonthPickerState_year1900_isCorrect() {
+        val state = YearMonthPickerState(
+            initialYear = 1900,
+            initialMonth = 1
+        )
+
+        assertEquals(1900, state.selectedYear)
+    }
+
+    @Test
+    fun yearMonthPickerState_year2100_isCorrect() {
+        val state = YearMonthPickerState(
+            initialYear = 2100,
+            initialMonth = 12
+        )
+
+        assertEquals(2100, state.selectedYear)
+    }
+
+    @Test
+    fun yearMonthPickerState_currentYear_isCorrect() {
+        val state = YearMonthPickerState(
+            initialYear = 2025,
+            initialMonth = 1
+        )
+
+        assertEquals(2025, state.selectedYear)
+    }
+
+    // ==================== Month Boundary Tests ====================
+
+    @Test
+    fun yearMonthPickerState_allMonths_areValid() {
+        for (month in 1..12) {
+            val state = YearMonthPickerState(
+                initialYear = 2024,
+                initialMonth = month
+            )
+            assertEquals(month, state.selectedMonth, "Month $month should be correctly stored")
+        }
+    }
+
+    // ==================== State Independence Tests ====================
+
+    @Test
+    fun yearMonthPickerState_multipleInstances_areIndependent() {
+        val state1 = YearMonthPickerState(
+            initialYear = 2020,
+            initialMonth = 3
+        )
+
+        val state2 = YearMonthPickerState(
+            initialYear = 2024,
+            initialMonth = 9
+        )
+
+        assertEquals(2020, state1.selectedYear)
+        assertEquals(2024, state2.selectedYear)
+        assertEquals(3, state1.selectedMonth)
+        assertEquals(9, state2.selectedMonth)
+    }
+
+    @Test
+    fun yearMonthPickerState_sameValues_areEqual() {
+        val state1 = YearMonthPickerState(
+            initialYear = 2024,
+            initialMonth = 6
+        )
+
+        val state2 = YearMonthPickerState(
+            initialYear = 2024,
+            initialMonth = 6
+        )
+
+        assertEquals(state1.selectedYear, state2.selectedYear)
+        assertEquals(state1.selectedMonth, state2.selectedMonth)
+    }
+
+    @Test
+    fun yearMonthPickerState_differentValues_areNotEqual() {
+        val state1 = YearMonthPickerState(
+            initialYear = 2024,
+            initialMonth = 6
+        )
+
+        val state2 = YearMonthPickerState(
+            initialYear = 2025,
+            initialMonth = 7
+        )
+
+        assertNotEquals(state1.selectedYear, state2.selectedYear)
+        assertNotEquals(state1.selectedMonth, state2.selectedMonth)
+    }
+
+    // ==================== Special Date Tests ====================
+
+    @Test
+    fun yearMonthPickerState_leapYear_isCorrect() {
+        val state = YearMonthPickerState(
+            initialYear = 2024,
+            initialMonth = 2
+        )
+
+        assertEquals(2024, state.selectedYear)
+        assertEquals(2, state.selectedMonth)
+    }
+
+    @Test
+    fun yearMonthPickerState_centuryYear_isCorrect() {
+        val state = YearMonthPickerState(
+            initialYear = 2000,
+            initialMonth = 2
+        )
+
+        assertEquals(2000, state.selectedYear)
+        assertEquals(2, state.selectedMonth)
+    }
+
+    @Test
+    fun yearMonthPickerState_endOfYear_isCorrect() {
+        val state = YearMonthPickerState(
+            initialYear = 2024,
+            initialMonth = 12
+        )
+
+        assertEquals(2024, state.selectedYear)
+        assertEquals(12, state.selectedMonth)
+    }
+
+    @Test
+    fun yearMonthPickerState_startOfYear_isCorrect() {
+        val state = YearMonthPickerState(
+            initialYear = 2024,
+            initialMonth = 1
+        )
+
+        assertEquals(2024, state.selectedYear)
+        assertEquals(1, state.selectedMonth)
+    }
+}

From 3b298f4673951a5ed8f2d8481fdd8c9be5e79d98 Mon Sep 17 00:00:00 2001
From: Kez <kejprogramer0909@gmail.com>
Date: Fri, 2 Jan 2026 00:02:51 +0900
Subject: [PATCH 8/9] feat: Enhance DatePicker and Picker components with
 accessibility labels and improved semantics

---
 README.md                                     | 50 ++++++++++++++++++-
 .../kotlin/com/kez/picker/Picker.kt           | 45 +++++++++++++++--
 .../kotlin/com/kez/picker/date/DatePicker.kt  |  9 ++--
 .../com/kez/picker/date/YearMonthPicker.kt    |  6 ++-
 .../kotlin/com/kez/picker/time/TimePicker.kt  | 15 +++---
 5 files changed, 108 insertions(+), 17 deletions(-)

diff --git a/README.md b/README.md
index 3db8d59..d90720a 100644
--- a/README.md
+++ b/README.md
@@ -9,9 +9,12 @@ It provides consistent UI components across Android, iOS, Desktop (JVM), and Web
 
 *   **Multiplatform Support**: seamless integration for Android, iOS, Desktop (JVM), and Web (Wasm).
 *   **TimePicker**: Supports both 12-hour (AM/PM) and 24-hour formats.
+* **DatePicker**: A complete date picker for selecting year, month, and day with automatic day
+  validation.
 *   **YearMonthPicker**: A dedicated component for selecting years and months.
 *   **Customizable**: Extensible API allowing custom content rendering, styling, and configuration.
-*   **State Management**: simplified state handling with `rememberTimePickerState` and `rememberYearMonthPickerState`.
+* **State Management**: simplified state handling with `rememberTimePickerState`,
+  `rememberDatePickerState`, and `rememberYearMonthPickerState`.
 *   **Accessibility**: Built with accessibility in mind, supporting screen readers and navigation.
 
 ## Installation
@@ -92,6 +95,34 @@ fun TimePicker12hExample() {
 }
 ```
 
+### DatePicker
+
+Use `DatePicker` for selecting a complete date (year, month, and day). The component automatically
+adjusts the day when the selected month changes (e.g., Feb 30 → Feb 28).
+
+```kotlin
+import androidx.compose.runtime.Composable
+import com.kez.picker.date.DatePicker
+import com.kez.picker.rememberDatePickerState
+import com.kez.picker.util.currentDate
+
+@Composable
+fun DatePickerExample() {
+    val state = rememberDatePickerState(
+        initialYear = currentDate().year,
+        initialMonth = currentDate().monthNumber,
+        initialDay = currentDate().dayOfMonth
+    )
+
+    DatePicker(
+        state = state
+    )
+
+    // Access selected values
+    // state.selectedYear, state.selectedMonth, state.selectedDay
+}
+```
+
 ### YearMonthPicker
 
 Use `YearMonthPicker` for selecting a specific month in a year.
@@ -163,6 +194,23 @@ fun BottomSheetPickerExample() {
 | `selectedTextStyle` | Style for selected item. | `22.sp` |
 | `dividerColor` | Color of the selection dividers. | `LocalContentColor.current` |
 
+### DatePicker
+
+| Parameter           | Description                             | Default                     |
+|:--------------------|:----------------------------------------|:----------------------------|
+| `state`             | The state object to control the picker. | `rememberDatePickerState()` |
+| `startLocalDate`    | The initial date to set the picker to.  | `currentDate`               |
+| `yearItems`         | List of years available for selection.  | `1900..2100`                |
+| `monthItems`        | List of months available for selection. | `1..12`                     |
+| `visibleItemsCount` | Number of items visible in the list.    | `3`                         |
+
+**DatePickerState Properties:**
+
+- `selectedYear`: The currently selected year.
+- `selectedMonth`: The currently selected month (1-12).
+- `selectedDay`: The currently selected day (1-31, auto-adjusted based on month).
+- `maxDay`: The maximum valid day for the selected year and month.
+
 ### YearMonthPicker
 
 | Parameter | Description | Default |
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt
index 9971a7c..5f5a045 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt
@@ -31,11 +31,18 @@ import androidx.compose.ui.graphics.Shape
 import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.graphics.lerp
 import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.semantics.CollectionInfo
+import androidx.compose.ui.semantics.CollectionItemInfo
+import androidx.compose.ui.semantics.LiveRegionMode
 import androidx.compose.ui.semantics.Role
+import androidx.compose.ui.semantics.collectionInfo
+import androidx.compose.ui.semantics.collectionItemInfo
 import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.liveRegion
 import androidx.compose.ui.semantics.role
 import androidx.compose.ui.semantics.selected
 import androidx.compose.ui.semantics.semantics
+import androidx.compose.ui.semantics.stateDescription
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.tooling.preview.Preview
@@ -70,11 +77,12 @@ private const val INFINITE_SCROLL_MULTIPLIER = 1000
  * @param itemPadding The padding around each item.
  * @param fadingEdgeGradient The gradient to use for fading edges.
  * @param horizontalAlignment The horizontal alignment of items.
- * @param itemTextAlignment The vertical alignment of the text within items.
+ * @param verticalAlignment The vertical alignment of the text within items.
  * @param dividerThickness The thickness of the dividers.
  * @param dividerShape The shape of the dividers.
  * @param isDividerVisible Whether the divider should be visible.
  * @param isInfinity Whether the picker should loop infinitely.
+ * @param pickerLabel Accessibility label for the picker (e.g., "Hour", "Minute", "Year").
  * @param content Optional custom content composable for rendering each item.
  */
 @Composable
@@ -90,11 +98,12 @@ fun <T> Picker(
     itemPadding: PaddingValues = PickerDefaults.ItemPadding,
     fadingEdgeGradient: Brush = PickerDefaults.fadingEdgeGradient(),
     horizontalAlignment: Alignment.Horizontal = Alignment.CenterHorizontally,
-    itemTextAlignment: Alignment.Vertical = Alignment.CenterVertically,
+    verticalAlignment: Alignment.Vertical = Alignment.CenterVertically,
     dividerThickness: Dp = PickerDefaults.DividerThickness,
     dividerShape: Shape = PickerDefaults.DividerShape,
     isDividerVisible: Boolean = true,
     isInfinity: Boolean = true,
+    pickerLabel: String? = null,
     content: @Composable ((T) -> Unit)? = null
 ) {
     require(items.isNotEmpty()) { "Items list must not be empty" }
@@ -131,7 +140,11 @@ fun <T> Picker(
             }
         }
 
-    fun getItem(index: Int) = adjustedItems[index % adjustedItems.size]
+    fun getItem(index: Int): T? {
+        if (adjustedItems.isEmpty()) return null
+        val safeIndex = index.mod(adjustedItems.size)
+        return adjustedItems.getOrNull(safeIndex)
+    }
 
     val listState = rememberLazyListState(initialFirstVisibleItemIndex = listStartIndex)
     val flingBehavior = rememberSnapFlingBehavior(lazyListState = listState)
@@ -164,7 +177,17 @@ fun <T> Picker(
             .collect { item -> state.selectedItem = item }
     }
 
-    Box(modifier = modifier) {
+    Box(
+        modifier = modifier.semantics {
+            // Provide picker-level accessibility information
+            pickerLabel?.let { label ->
+                contentDescription = "$label picker, currently selected: ${state.selectedItem}"
+                stateDescription = "Selected: ${state.selectedItem}"
+                liveRegion = LiveRegionMode.Polite
+            }
+            collectionInfo = CollectionInfo(rowCount = items.size, columnCount = 1)
+        }
+    ) {
         Box(
             modifier = Modifier
                 .align(Alignment.Center)
@@ -234,6 +257,7 @@ fun <T> Picker(
                 val item = getItem(index)
                 val isSelected = item == state.selectedItem
                 val itemDescription = item?.toString() ?: ""
+                val itemIndex = if (isInfinity) index % items.size else (index - 1).coerceAtLeast(0)
 
                 Box(
                     modifier = Modifier
@@ -242,8 +266,19 @@ fun <T> Picker(
                         .semantics {
                             if (item != null) {
                                 role = Role.Button
-                                contentDescription = itemDescription
+                                // Enhanced content description with picker context
+                                contentDescription = if (pickerLabel != null) {
+                                    "$pickerLabel: $itemDescription${if (isSelected) ", selected" else ""}"
+                                } else {
+                                    "$itemDescription${if (isSelected) ", selected" else ""}"
+                                }
                                 selected = isSelected
+                                collectionItemInfo = CollectionItemInfo(
+                                    rowIndex = itemIndex,
+                                    rowSpan = 1,
+                                    columnIndex = 0,
+                                    columnSpan = 1
+                                )
                             }
                         }
                         .clickable(
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
index f481c5b..300de3d 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
@@ -119,10 +119,11 @@ fun DatePicker(
                     itemPadding = itemPadding,
                     fadingEdgeGradient = fadingEdgeGradient,
                     horizontalAlignment = horizontalAlignment,
-                    itemTextAlignment = verticalAlignment,
+                    verticalAlignment = verticalAlignment,
                     dividerThickness = dividerThickness,
                     dividerShape = dividerShape,
                     isDividerVisible = isDividerVisible,
+                    pickerLabel = "Year"
                 )
 
                 // Month Picker
@@ -138,10 +139,11 @@ fun DatePicker(
                     itemPadding = itemPadding,
                     fadingEdgeGradient = fadingEdgeGradient,
                     horizontalAlignment = horizontalAlignment,
-                    itemTextAlignment = verticalAlignment,
+                    verticalAlignment = verticalAlignment,
                     dividerThickness = dividerThickness,
                     dividerShape = dividerShape,
                     isDividerVisible = isDividerVisible,
+                    pickerLabel = "Month"
                 )
 
                 // Day Picker
@@ -158,10 +160,11 @@ fun DatePicker(
                     isInfinity = false,
                     fadingEdgeGradient = fadingEdgeGradient,
                     horizontalAlignment = horizontalAlignment,
-                    itemTextAlignment = verticalAlignment,
+                    verticalAlignment = verticalAlignment,
                     dividerThickness = dividerThickness,
                     dividerShape = dividerShape,
                     isDividerVisible = isDividerVisible,
+                    pickerLabel = "Day"
                 )
             }
         }
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt
index 41caab7..1c029ab 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt
@@ -104,10 +104,11 @@ fun YearMonthPicker(
                     itemPadding = itemPadding,
                     fadingEdgeGradient = fadingEdgeGradient,
                     horizontalAlignment = horizontalAlignment,
-                    itemTextAlignment = verticalAlignment,
+                    verticalAlignment = verticalAlignment,
                     dividerThickness = dividerThickness,
                     dividerShape = dividerShape,
                     isDividerVisible = isDividerVisible,
+                    pickerLabel = "Year"
                 )
                 Picker(
                     state = state.monthState,
@@ -121,10 +122,11 @@ fun YearMonthPicker(
                     itemPadding = itemPadding,
                     fadingEdgeGradient = fadingEdgeGradient,
                     horizontalAlignment = horizontalAlignment,
-                    itemTextAlignment = verticalAlignment,
+                    verticalAlignment = verticalAlignment,
                     dividerThickness = dividerThickness,
                     dividerShape = dividerShape,
                     isDividerVisible = isDividerVisible,
+                    pickerLabel = "Month"
                 )
             }
         }
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt
index e5e4fa4..0ae773b 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt
@@ -126,11 +126,12 @@ fun TimePicker(
                         startIndex = periodStartIndex,
                         fadingEdgeGradient = fadingEdgeGradient,
                         horizontalAlignment = horizontalAlignment,
-                        itemTextAlignment = verticalAlignment,
+                        verticalAlignment = verticalAlignment,
                         dividerThickness = dividerThickness,
                         dividerShape = dividerShape,
                         isDividerVisible = isDividerVisible,
-                        isInfinity = false
+                        isInfinity = false,
+                        pickerLabel = "Period"
                     )
                     Spacer(modifier = Modifier.width(spacingBetweenPickers))
                 }
@@ -146,10 +147,11 @@ fun TimePicker(
                     itemPadding = itemPadding,
                     fadingEdgeGradient = fadingEdgeGradient,
                     horizontalAlignment = horizontalAlignment,
-                    itemTextAlignment = verticalAlignment,
+                    verticalAlignment = verticalAlignment,
                     dividerThickness = dividerThickness,
                     dividerShape = dividerShape,
-                    isDividerVisible = isDividerVisible
+                    isDividerVisible = isDividerVisible,
+                    pickerLabel = "Hour"
                 )
                 Spacer(modifier = Modifier.width(spacingBetweenPickers))
                 Picker(
@@ -164,10 +166,11 @@ fun TimePicker(
                     itemPadding = itemPadding,
                     fadingEdgeGradient = fadingEdgeGradient,
                     horizontalAlignment = horizontalAlignment,
-                    itemTextAlignment = verticalAlignment,
+                    verticalAlignment = verticalAlignment,
                     dividerThickness = dividerThickness,
                     dividerShape = dividerShape,
-                    isDividerVisible = isDividerVisible
+                    isDividerVisible = isDividerVisible,
+                    pickerLabel = "Minute"
                 )
             }
         }

From 373e9b4e82068db23e9df76333f7e7c1cf08b625 Mon Sep 17 00:00:00 2001
From: Kez <kejprogramer0909@gmail.com>
Date: Wed, 20 May 2026 00:12:16 +0900
Subject: [PATCH 9/9] fix: stabilize date picker release readiness

---
 .github/workflows/integration-build-test.yml  | 69 ++++++++-------
 README.md                                     | 49 ++++++-----
 README_KO.md                                  | 83 +++++++++++++++----
 datetimepicker/build.gradle.kts               | 10 +--
 .../kotlin/com/kez/picker/Picker.kt           | 18 ++--
 .../kotlin/com/kez/picker/date/DatePicker.kt  | 70 +++++++---------
 .../com/kez/picker/date/DatePickerState.kt    |  9 +-
 .../com/kez/picker/date/YearMonthPicker.kt    | 15 ++--
 .../kotlin/com/kez/picker/time/TimePicker.kt  | 28 +++----
 .../kotlin/com/kez/picker/PickerUtilsTest.kt  | 16 +++-
 .../kez/picker/date/DatePickerStateTest.kt    | 16 +++-
 gradle.properties                             |  2 +-
 .../kotlin/com/kez/picker/sample/App.kt       |  6 +-
 .../kez/picker/sample/ui/navigation/Screen.kt |  2 +-
 .../ui/screen/BackgroundStylePickerScreen.kt  | 47 ++++++-----
 .../ui/screen/BottomSheetSampleScreen.kt      | 45 ++++++----
 .../ui/screen/DatePickerSampleScreen.kt       | 19 +++--
 .../kez/picker/sample/ui/screen/HomeScreen.kt |  8 +-
 .../ui/screen/IntegratedPickerScreen.kt       | 53 +++++++-----
 .../ui/screen/TimePickerSampleScreen.kt       |  6 +-
 .../ui/screen/YearMonthPickerSampleScreen.kt  |  2 +-
 21 files changed, 346 insertions(+), 227 deletions(-)

diff --git a/.github/workflows/integration-build-test.yml b/.github/workflows/integration-build-test.yml
index 4e92381..5c8855c 100644
--- a/.github/workflows/integration-build-test.yml
+++ b/.github/workflows/integration-build-test.yml
@@ -12,7 +12,8 @@ permissions:
   contents: read
 
 env:
-  MODULE: ":datetimepicker"
+  LIBRARY_MODULE: ":datetimepicker"
+  SAMPLE_MODULE: ":sample"
 jobs:
 
   linux-builds:
@@ -26,14 +27,15 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: gradle/wrapper-validation-action@v2
+      - uses: gradle/actions/wrapper-validation@v4
 
       - name: Set up JDK 17
         uses: actions/setup-java@v4
         with:
           java-version: '17'
           distribution: 'temurin'
-          cache: 'gradle'
+
+      - uses: gradle/actions/setup-gradle@v4
 
       # Android Set Up
       - name: Set up Android SDK
@@ -44,39 +46,42 @@ jobs:
         if: matrix.target == 'android'
         run: |
           sdkmanager "platform-tools" \
-                     "platforms;android-34" \
-                     "build-tools;34.0.0" || true
-          yes | sdkmanager --licenses || true
+                     "platforms;android-36" \
+                     "build-tools;36.0.0"
+          yes | sdkmanager --licenses
 
       # Android Build/Unit Test
       - name: Gradle Build • Android
         if: matrix.target == 'android'
-        uses: gradle/gradle-build-action@v3
-        with:
-          arguments: |
-            ${{ env.MODULE }}:clean
-            ${{ env.MODULE }}:assembleRelease
-            ${{ env.MODULE }}:testReleaseUnitTest
+        run: |
+          ./gradlew \
+            ${{ env.LIBRARY_MODULE }}:clean \
+            ${{ env.LIBRARY_MODULE }}:assembleRelease \
+            ${{ env.LIBRARY_MODULE }}:testReleaseUnitTest \
+            ${{ env.SAMPLE_MODULE }}:assembleDebug \
+            --no-daemon
 
       # Web(WASM) Build/Test
       - name: Gradle Build • Web (WASM)
         if: matrix.target == 'wasm'
-        uses: gradle/gradle-build-action@v3
-        with:
-          arguments: |
-            ${{ env.MODULE }}:clean
-            ${{ env.MODULE }}:wasmJsBrowserDistribution
-            ${{ env.MODULE }}:wasmJsTest
+        run: |
+          ./gradlew \
+            ${{ env.LIBRARY_MODULE }}:clean \
+            ${{ env.LIBRARY_MODULE }}:wasmJsBrowserDistribution \
+            ${{ env.LIBRARY_MODULE }}:wasmJsTest \
+            ${{ env.SAMPLE_MODULE }}:wasmJsBrowserDistribution \
+            --no-daemon
 
       # Desktop(JVM) Build/Test
       - name: Gradle Build • Desktop (JVM)
         if: matrix.target == 'desktop'
-        uses: gradle/gradle-build-action@v3
-        with:
-          arguments: |
-            ${{ env.MODULE }}:clean
-            ${{ env.MODULE }}:desktopJar
-            ${{ env.MODULE }}:desktopTest
+        run: |
+          ./gradlew \
+            ${{ env.LIBRARY_MODULE }}:clean \
+            ${{ env.LIBRARY_MODULE }}:desktopJar \
+            ${{ env.LIBRARY_MODULE }}:desktopTest \
+            ${{ env.SAMPLE_MODULE }}:compileKotlinDesktop \
+            --no-daemon
 
   ios-build-and-test:
     name: macOS • iOS Simulator Test
@@ -85,14 +90,15 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: gradle/wrapper-validation-action@v2
+      - uses: gradle/actions/wrapper-validation@v4
 
       - name: Set up JDK 17
         uses: actions/setup-java@v4
         with:
           java-version: '17'
           distribution: 'temurin'
-          cache: 'gradle'
+
+      - uses: gradle/actions/setup-gradle@v4
 
       - name: Boot iOS Simulator (iPhone 15)
         run: |
@@ -104,8 +110,9 @@ jobs:
 
       # iOS Simulator Unit Test
       - name: Gradle Build & Test • iOS
-        uses: gradle/gradle-build-action@v3
-        with:
-          arguments: |
-            ${{ env.MODULE }}:clean
-            ${{ env.MODULE }}:iosSimulatorArm64Test
+        run: |
+          ./gradlew \
+            ${{ env.LIBRARY_MODULE }}:clean \
+            ${{ env.LIBRARY_MODULE }}:iosSimulatorArm64Test \
+            ${{ env.SAMPLE_MODULE }}:compileKotlinIosSimulatorArm64 \
+            --no-daemon
diff --git a/README.md b/README.md
index d90720a..2518536 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,7 @@ Add the dependency to your version catalog or build file.
 
 ```toml
 [versions]
-composeDateTimePicker = "0.4.0"
+composeDateTimePicker = "0.5.0"
 
 [libraries]
 compose-date-time-picker = { module = "io.github.kez-lab:compose-date-time-picker", version.ref = "composeDateTimePicker" }
@@ -35,7 +35,7 @@ compose-date-time-picker = { module = "io.github.kez-lab:compose-date-time-picke
 
 ```kotlin
 dependencies {
-    implementation("io.github.kez-lab:compose-date-time-picker:0.4.0")
+    implementation("io.github.kez-lab:compose-date-time-picker:0.5.0")
 }
 ```
 
@@ -58,8 +58,8 @@ import com.kez.picker.util.currentMinute
 @Composable
 fun TimePicker24hExample() {
     val state = rememberTimePickerState(
-        initialHour = currentHour,
-        initialMinute = currentMinute,
+        initialHour = currentHour(),
+        initialMinute = currentMinute(),
         timeFormat = TimeFormat.HOUR_24
     )
 
@@ -76,7 +76,6 @@ import androidx.compose.runtime.Composable
 import com.kez.picker.time.TimePicker
 import com.kez.picker.rememberTimePickerState
 import com.kez.picker.util.TimeFormat
-import com.kez.picker.util.TimePeriod
 import com.kez.picker.util.currentHour
 import com.kez.picker.util.currentMinute
 
@@ -84,8 +83,8 @@ import com.kez.picker.util.currentMinute
 fun TimePicker12hExample() {
     // Handling of 12-hour format conversion is now done internally by the state
     val state = rememberTimePickerState(
-        initialHour = currentHour,
-        initialMinute = currentMinute,
+        initialHour = currentHour(),
+        initialMinute = currentMinute(),
         timeFormat = TimeFormat.HOUR_12
     )
 
@@ -103,15 +102,16 @@ adjusts the day when the selected month changes (e.g., Feb 30 → Feb 28).
 ```kotlin
 import androidx.compose.runtime.Composable
 import com.kez.picker.date.DatePicker
-import com.kez.picker.rememberDatePickerState
+import com.kez.picker.date.rememberDatePickerState
 import com.kez.picker.util.currentDate
+import com.kez.picker.util.currentMonth
 
 @Composable
 fun DatePickerExample() {
     val state = rememberDatePickerState(
         initialYear = currentDate().year,
-        initialMonth = currentDate().monthNumber,
-        initialDay = currentDate().dayOfMonth
+        initialMonth = currentMonth(),
+        initialDay = currentDate().day
     )
 
     DatePicker(
@@ -132,12 +132,13 @@ import androidx.compose.runtime.Composable
 import com.kez.picker.date.YearMonthPicker
 import com.kez.picker.rememberYearMonthPickerState
 import com.kez.picker.util.currentDate
+import com.kez.picker.util.currentMonth
 
 @Composable
 fun YearMonthPickerExample() {
     val state = rememberYearMonthPickerState(
-        initialYear = currentDate.year,
-        initialMonth = currentDate.monthNumber
+        initialYear = currentDate().year,
+        initialMonth = currentMonth()
     )
 
     YearMonthPicker(
@@ -155,7 +156,6 @@ import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import com.kez.picker.time.TimePicker
 import com.kez.picker.rememberTimePickerState
-import kotlinx.coroutines.launch
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -163,7 +163,6 @@ fun BottomSheetPickerExample() {
     var showBottomSheet by remember { mutableStateOf(false) }
     val sheetState = rememberModalBottomSheetState()
     val state = rememberTimePickerState()
-    val scope = rememberCoroutineScope()
 
     Button(onClick = { showBottomSheet = true }) {
         Text("Select Time")
@@ -188,21 +187,25 @@ fun BottomSheetPickerExample() {
 | Parameter | Description | Default |
 | :--- | :--- | :--- |
 | `state` | The state object to control the picker. | `rememberTimePickerState()` |
-| `startTime` | The initial time to set the picker to. | `currentDateTime` |
+| `startTime` | Legacy initial time parameter. Prefer setting initial values in `rememberTimePickerState`. | `currentDateTime()` |
+| `minuteItems` | Minute values available for selection. | `0..59` |
+| `hourItems` | Hour values available for selection. | `0..23` or `1..12` |
 | `visibleItemsCount` | Number of items visible in the list. | `3` |
-| `textStyle` | Style for unselected items. | `16.sp` |
-| `selectedTextStyle` | Style for selected item. | `22.sp` |
-| `dividerColor` | Color of the selection dividers. | `LocalContentColor.current` |
+| `colors` | Colors for text, selected text, dividers, and selected item background. | `PickerDefaults.colors()` |
+| `textStyles` | Text styles for selected and unselected items. | `PickerDefaults.textStyles()` |
+| `isDividerVisible` | Whether selection dividers are visible. | `true` |
 
 ### DatePicker
 
 | Parameter           | Description                             | Default                     |
 |:--------------------|:----------------------------------------|:----------------------------|
 | `state`             | The state object to control the picker. | `rememberDatePickerState()` |
-| `startLocalDate`    | The initial date to set the picker to.  | `currentDate`               |
-| `yearItems`         | List of years available for selection.  | `1900..2100`                |
+| `startLocalDate`    | Legacy initial date parameter. Prefer setting initial values in `rememberDatePickerState`. | `currentDate()`             |
+| `yearItems`         | List of years available for selection.  | `1000..9999`                |
 | `monthItems`        | List of months available for selection. | `1..12`                     |
 | `visibleItemsCount` | Number of items visible in the list.    | `3`                         |
+| `colors`            | Colors for text, selected text, dividers, and selected item background. | `PickerDefaults.colors()` |
+| `textStyles`        | Text styles for selected and unselected items. | `PickerDefaults.textStyles()` |
 
 **DatePickerState Properties:**
 
@@ -216,10 +219,12 @@ fun BottomSheetPickerExample() {
 | Parameter | Description | Default |
 | :--- | :--- | :--- |
 | `state` | The state object to control the picker. | `rememberYearMonthPickerState()` |
-| `startLocalDate` | The initial date to set the picker to. | `currentDate` |
-| `yearItems` | List of years available for selection. | `1900..2100` |
+| `startLocalDate` | Legacy initial date parameter. Prefer setting initial values in `rememberYearMonthPickerState`. | `currentDate()` |
+| `yearItems` | List of years available for selection. | `1000..9999` |
 | `monthItems` | List of months available for selection. | `1..12` |
 | `visibleItemsCount` | Number of items visible in the list. | `3` |
+| `colors` | Colors for text, selected text, dividers, and selected item background. | `PickerDefaults.colors()` |
+| `textStyles` | Text styles for selected and unselected items. | `PickerDefaults.textStyles()` |
 
 ## License
 
diff --git a/README_KO.md b/README_KO.md
index 3b13865..9dc05ea 100644
--- a/README_KO.md
+++ b/README_KO.md
@@ -9,9 +9,10 @@ Android, iOS, Desktop (JVM), Web (Wasm) 등 다양한 플랫폼에서 일관된
 
 *   **멀티플랫폼 지원**: Android, iOS, Desktop (JVM), Web (Wasm) 환경을 지원하며 원활한 통합이 가능합니다.
 *   **TimePicker**: 12시간(오전/오후) 및 24시간 형식을 모두 지원합니다.
+*   **DatePicker**: 연도, 월, 일을 함께 선택하고 월/윤년에 맞춰 일을 자동 보정합니다.
 *   **YearMonthPicker**: 년도와 월을 선택할 수 있는 전용 컴포넌트를 제공합니다.
 *   **커스터마이징**: 커스텀 아이템 렌더링, 스타일링, 구성 변경이 가능한 유연한 API를 제공합니다.
-*   **상태 관리**: `rememberTimePickerState` 및 `rememberYearMonthPickerState`를 통해 간편하게 상태를 관리할 수 있습니다.
+*   **상태 관리**: `rememberTimePickerState`, `rememberDatePickerState`, `rememberYearMonthPickerState`를 통해 간편하게 상태를 관리할 수 있습니다.
 *   **접근성**: 스크린 리더 및 내비게이션 지원 등 접근성을 고려하여 설계되었습니다.
 
 ## 설치 방법
@@ -22,7 +23,7 @@ Android, iOS, Desktop (JVM), Web (Wasm) 등 다양한 플랫폼에서 일관된
 
 ```toml
 [versions]
-composeDateTimePicker = "0.4.0"
+composeDateTimePicker = "0.5.0"
 
 [libraries]
 compose-date-time-picker = { module = "io.github.kez-lab:compose-date-time-picker", version.ref = "composeDateTimePicker" }
@@ -32,7 +33,7 @@ compose-date-time-picker = { module = "io.github.kez-lab:compose-date-time-picke
 
 ```kotlin
 dependencies {
-    implementation("io.github.kez-lab:compose-date-time-picker:0.4.0")
+    implementation("io.github.kez-lab:compose-date-time-picker:0.5.0")
 }
 ```
 
@@ -55,8 +56,8 @@ import com.kez.picker.util.currentMinute
 @Composable
 fun TimePicker24hExample() {
     val state = rememberTimePickerState(
-        initialHour = currentHour,
-        initialMinute = currentMinute,
+        initialHour = currentHour(),
+        initialMinute = currentMinute(),
         timeFormat = TimeFormat.HOUR_24
     )
 
@@ -73,7 +74,6 @@ import androidx.compose.runtime.Composable
 import com.kez.picker.time.TimePicker
 import com.kez.picker.rememberTimePickerState
 import com.kez.picker.util.TimeFormat
-import com.kez.picker.util.TimePeriod
 import com.kez.picker.util.currentHour
 import com.kez.picker.util.currentMinute
 
@@ -81,8 +81,8 @@ import com.kez.picker.util.currentMinute
 fun TimePicker12hExample() {
     // 12시간 형식 변환은 이제 state 내부에서 처리됩니다.
     val state = rememberTimePickerState(
-        initialHour = currentHour,
-        initialMinute = currentMinute,
+        initialHour = currentHour(),
+        initialMinute = currentMinute(),
         timeFormat = TimeFormat.HOUR_12
     )
 
@@ -92,6 +92,31 @@ fun TimePicker12hExample() {
 }
 ```
 
+### DatePicker
+
+연도, 월, 일을 함께 선택할 때 `DatePicker`를 사용합니다. 선택된 월에 유효하지 않은 일이 있으면 자동으로 보정됩니다.
+
+```kotlin
+import androidx.compose.runtime.Composable
+import com.kez.picker.date.DatePicker
+import com.kez.picker.date.rememberDatePickerState
+import com.kez.picker.util.currentDate
+import com.kez.picker.util.currentMonth
+
+@Composable
+fun DatePickerExample() {
+    val state = rememberDatePickerState(
+        initialYear = currentDate().year,
+        initialMonth = currentMonth(),
+        initialDay = currentDate().day
+    )
+
+    DatePicker(state = state)
+
+    // state.selectedYear, state.selectedMonth, state.selectedDay
+}
+```
+
 ### YearMonthPicker
 
 특정 연도와 월을 선택할 때 `YearMonthPicker`를 사용합니다.
@@ -101,12 +126,13 @@ import androidx.compose.runtime.Composable
 import com.kez.picker.date.YearMonthPicker
 import com.kez.picker.rememberYearMonthPickerState
 import com.kez.picker.util.currentDate
+import com.kez.picker.util.currentMonth
 
 @Composable
 fun YearMonthPickerExample() {
     val state = rememberYearMonthPickerState(
-        initialYear = currentDate.year,
-        initialMonth = currentDate.monthNumber
+        initialYear = currentDate().year,
+        initialMonth = currentMonth()
     )
 
     YearMonthPicker(
@@ -124,7 +150,6 @@ import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import com.kez.picker.time.TimePicker
 import com.kez.picker.rememberTimePickerState
-import kotlinx.coroutines.launch
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -132,7 +157,6 @@ fun BottomSheetPickerExample() {
     var showBottomSheet by remember { mutableStateOf(false) }
     val sheetState = rememberModalBottomSheetState()
     val state = rememberTimePickerState()
-    val scope = rememberCoroutineScope()
 
     Button(onClick = { showBottomSheet = true }) {
         Text("시간 선택")
@@ -157,21 +181,44 @@ fun BottomSheetPickerExample() {
 | 파라미터 | 설명 | 기본값 |
 | :--- | :--- | :--- |
 | `state` | Picker를 제어하기 위한 상태 객체입니다. | `rememberTimePickerState()` |
-| `startTime` | Picker에 설정될 초기 시간입니다. | `currentDateTime` |
+| `startTime` | 레거시 초기 시간 파라미터입니다. 초기값은 `rememberTimePickerState`에서 설정하는 방식을 권장합니다. | `currentDateTime()` |
+| `minuteItems` | 선택 가능한 분 목록입니다. | `0..59` |
+| `hourItems` | 선택 가능한 시간 목록입니다. | `0..23` 또는 `1..12` |
+| `visibleItemsCount` | 리스트에 표시될 아이템의 개수입니다. | `3` |
+| `colors` | 텍스트, 선택 텍스트, 구분선, 선택 영역 배경 색상입니다. | `PickerDefaults.colors()` |
+| `textStyles` | 선택/비선택 아이템의 텍스트 스타일입니다. | `PickerDefaults.textStyles()` |
+| `isDividerVisible` | 선택 영역 구분선 표시 여부입니다. | `true` |
+
+### DatePicker
+
+| 파라미터 | 설명 | 기본값 |
+| :--- | :--- | :--- |
+| `state` | Picker를 제어하기 위한 상태 객체입니다. | `rememberDatePickerState()` |
+| `startLocalDate` | 레거시 초기 날짜 파라미터입니다. 초기값은 `rememberDatePickerState`에서 설정하는 방식을 권장합니다. | `currentDate()` |
+| `yearItems` | 선택 가능한 연도 목록입니다. | `1000..9999` |
+| `monthItems` | 선택 가능한 월 목록입니다. | `1..12` |
 | `visibleItemsCount` | 리스트에 표시될 아이템의 개수입니다. | `3` |
-| `textStyle` | 선택되지 않은 아이템의 텍스트 스타일입니다. | `16.sp` |
-| `selectedTextStyle` | 선택된 아이템의 텍스트 스타일입니다. | `22.sp` |
-| `dividerColor` | 구분선의 색상입니다. | `LocalContentColor.current` |
+| `colors` | 텍스트, 선택 텍스트, 구분선, 선택 영역 배경 색상입니다. | `PickerDefaults.colors()` |
+| `textStyles` | 선택/비선택 아이템의 텍스트 스타일입니다. | `PickerDefaults.textStyles()` |
+
+**DatePickerState 속성:**
+
+- `selectedYear`: 현재 선택된 연도입니다.
+- `selectedMonth`: 현재 선택된 월입니다. (1-12)
+- `selectedDay`: 현재 선택된 일입니다. 선택된 월에 맞게 자동 보정됩니다.
+- `maxDay`: 현재 선택된 연도/월에서 선택 가능한 최대 일입니다.
 
 ### YearMonthPicker
 
 | 파라미터 | 설명 | 기본값 |
 | :--- | :--- | :--- |
 | `state` | Picker를 제어하기 위한 상태 객체입니다. | `rememberYearMonthPickerState()` |
-| `startLocalDate` | Picker에 설정될 초기 날짜입니다. | `currentDate` |
-| `yearItems` | 선택 가능한 연도 목록입니다. | `1900..2100` |
+| `startLocalDate` | 레거시 초기 날짜 파라미터입니다. 초기값은 `rememberYearMonthPickerState`에서 설정하는 방식을 권장합니다. | `currentDate()` |
+| `yearItems` | 선택 가능한 연도 목록입니다. | `1000..9999` |
 | `monthItems` | 선택 가능한 월 목록입니다. | `1..12` |
 | `visibleItemsCount` | 리스트에 표시될 아이템의 개수입니다. | `3` |
+| `colors` | 텍스트, 선택 텍스트, 구분선, 선택 영역 배경 색상입니다. | `PickerDefaults.colors()` |
+| `textStyles` | 선택/비선택 아이템의 텍스트 스타일입니다. | `PickerDefaults.textStyles()` |
 
 ## 라이선스
 
diff --git a/datetimepicker/build.gradle.kts b/datetimepicker/build.gradle.kts
index ef88ebe..403e994 100644
--- a/datetimepicker/build.gradle.kts
+++ b/datetimepicker/build.gradle.kts
@@ -34,14 +34,14 @@ kotlin {
 
     sourceSets {
         commonMain.dependencies {
-            implementation(libs.compose.runtime)
-            implementation(libs.compose.foundation)
+            api(libs.compose.runtime)
+            api(libs.compose.foundation)
+            api(libs.compose.ui)
+            api(libs.kotlinx.datetime)
+
             implementation(libs.compose.material3)
-            implementation(libs.compose.ui)
             implementation(libs.compose.ui.tooling.preview)
             implementation(libs.compose.components.resources)
-
-            implementation(libs.kotlinx.datetime)
             implementation(libs.kotlinx.coroutines.core)
         }
 
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt
index 5f5a045..c996d59 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/Picker.kt
@@ -119,7 +119,7 @@ fun <T> Picker(
     val scope = rememberCoroutineScope()
 
     val adjustedItems = if (!isInfinity) {
-        listOf(null) + items + listOf(null)
+        List(visibleItemsMiddle) { null } + items + List(visibleItemsMiddle) { null }
     } else {
         items
     }
@@ -136,14 +136,18 @@ fun <T> Picker(
             if (isInfinity) {
                 listScrollMiddle - listScrollMiddle % adjustedItems.size - visibleItemsMiddle + startIndex
             } else {
-                startIndex + 1
+                startIndex
             }
         }
 
     fun getItem(index: Int): T? {
         if (adjustedItems.isEmpty()) return null
-        val safeIndex = index.mod(adjustedItems.size)
-        return adjustedItems.getOrNull(safeIndex)
+        return if (isInfinity) {
+            val safeIndex = index.mod(adjustedItems.size)
+            adjustedItems.getOrNull(safeIndex)
+        } else {
+            adjustedItems.getOrNull(index)
+        }
     }
 
     val listState = rememberLazyListState(initialFirstVisibleItemIndex = listStartIndex)
@@ -257,7 +261,11 @@ fun <T> Picker(
                 val item = getItem(index)
                 val isSelected = item == state.selectedItem
                 val itemDescription = item?.toString() ?: ""
-                val itemIndex = if (isInfinity) index % items.size else (index - 1).coerceAtLeast(0)
+                val itemIndex = if (isInfinity) {
+                    index % items.size
+                } else {
+                    (index - visibleItemsMiddle).coerceAtLeast(0)
+                }
 
                 Box(
                     modifier = Modifier
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
index 300de3d..fd1f55b 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePicker.kt
@@ -8,6 +8,7 @@ import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.key
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -15,12 +16,10 @@ import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Shape
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.Dp
-import com.kez.picker.DatePickerState
 import com.kez.picker.Picker
 import com.kez.picker.PickerColors
 import com.kez.picker.PickerDefaults
 import com.kez.picker.PickerTextStyles
-import com.kez.picker.rememberDatePickerState
 import com.kez.picker.util.MONTH_RANGE
 import com.kez.picker.util.YEAR_RANGE
 import com.kez.picker.util.currentDate
@@ -32,7 +31,7 @@ import kotlinx.datetime.LocalDate
  * @param modifier The modifier to be applied to the component.
  * @param pickerModifier The modifier to be applied to each picker.
  * @param state The state object to control the picker.
- * @param startLocalDate The initial date to display (relevant for initial index calculation if needed, though state handles values).
+ * @param startLocalDate Legacy initial date parameter. Prefer setting initial values in [state].
  * @param yearItems The list of year values to display.
  * @param monthItems The list of month values to display.
  * @param visibleItemsCount The number of items visible at once.
@@ -80,24 +79,13 @@ fun DatePicker(
             verticalArrangement = Arrangement.Center,
             modifier = Modifier.fillMaxWidth()
         ) {
+            val yearStartIndex = remember(yearItems) { yearItems.startIndexOf(state.selectedYear) }
+            val monthStartIndex = remember(monthItems) { monthItems.startIndexOf(state.selectedMonth) }
 
-            // Calculate initial indices based on startLocalDate logic if strictly needed,
-            // but usually we rely on the state's initial value. 
-            // However, Picker component uses `startIndex`. 
-            // We should sync them with state's initial values or just find index of state's current value.
-            
-            // To ensure 1:1 mapping with Picker's internal state on first render:
-            val yearStartIndex = remember { yearItems.indexOf(state.selectedYear) }
-            val monthStartIndex = remember { monthItems.indexOf(state.selectedMonth) }
-            // Day items change dynamically, so we can't fully pre-calculate a static list and index 
-            // without being careful.
-            
-            // Dynamic day items based on maxDay
             val maxDay = state.maxDay
             val dayItems = (1..maxDay).toList()
-            // Ensure selected day index is valid for the current dayItems
-            val dayStartIndex = remember(dayItems) { 
-                val index = dayItems.indexOf(state.selectedDay)
+            val dayStartIndex = remember(dayItems, state.selectedDay) {
+                val index = dayItems.indexOf(state.selectedDay.coerceIn(1, maxDay))
                 if (index >= 0) index else 0
             }
 
@@ -106,7 +94,6 @@ fun DatePicker(
                 horizontalArrangement = Arrangement.Center,
                 verticalAlignment = Alignment.CenterVertically
             ) {
-                // Year Picker
                 Picker(
                     state = state.yearState,
                     modifier = pickerModifier.weight(1.2f), // Give Year slightly more width
@@ -126,7 +113,6 @@ fun DatePicker(
                     pickerLabel = "Year"
                 )
 
-                // Month Picker
                 Picker(
                     state = state.monthState,
                     items = monthItems,
@@ -146,31 +132,35 @@ fun DatePicker(
                     pickerLabel = "Month"
                 )
 
-                // Day Picker
-                Picker(
-                    state = state.dayState,
-                    items = dayItems,
-                    startIndex = dayStartIndex,
-                    visibleItemsCount = visibleItemsCount,
-                    modifier = pickerModifier.weight(0.8f),
-                    colors = colors,
-                    textStyles = textStyles,
-                    selectedItemBackgroundShape = selectedItemBackgroundShape,
-                    itemPadding = itemPadding,
-                    isInfinity = false,
-                    fadingEdgeGradient = fadingEdgeGradient,
-                    horizontalAlignment = horizontalAlignment,
-                    verticalAlignment = verticalAlignment,
-                    dividerThickness = dividerThickness,
-                    dividerShape = dividerShape,
-                    isDividerVisible = isDividerVisible,
-                    pickerLabel = "Day"
-                )
+                key(maxDay) {
+                    Picker(
+                        state = state.dayState,
+                        items = dayItems,
+                        startIndex = dayStartIndex,
+                        visibleItemsCount = visibleItemsCount,
+                        modifier = pickerModifier.weight(0.8f),
+                        colors = colors,
+                        textStyles = textStyles,
+                        selectedItemBackgroundShape = selectedItemBackgroundShape,
+                        itemPadding = itemPadding,
+                        isInfinity = false,
+                        fadingEdgeGradient = fadingEdgeGradient,
+                        horizontalAlignment = horizontalAlignment,
+                        verticalAlignment = verticalAlignment,
+                        dividerThickness = dividerThickness,
+                        dividerShape = dividerShape,
+                        isDividerVisible = isDividerVisible,
+                        pickerLabel = "Day"
+                    )
+                }
             }
         }
     }
 }
 
+private fun <T> List<T>.startIndexOf(item: T): Int =
+    indexOf(item).takeIf { it >= 0 } ?: 0
+
 @Preview(name = "Default", group = "DatePicker", showBackground = true)
 @Composable
 fun DatePickerPreview() {
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePickerState.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePickerState.kt
index 6a25603..8d630b0 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePickerState.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/DatePickerState.kt
@@ -1,8 +1,9 @@
-package com.kez.picker
+package com.kez.picker.date
 
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.Stable
 import androidx.compose.runtime.remember
+import com.kez.picker.PickerState
 import com.kez.picker.util.currentDate
 import kotlinx.datetime.number
 
@@ -72,6 +73,12 @@ class DatePickerState(
         get() = daysInMonth(selectedYear, selectedMonth)
 
     init {
+        require(initialMonth in 1..12) {
+            "initialMonth must be in range [1, 12], but was $initialMonth"
+        }
+        require(initialDay >= 1) {
+            "initialDay must be greater than or equal to 1, but was $initialDay"
+        }
         val initialMaxDay = daysInMonth(initialYear, initialMonth)
         if (initialDay > initialMaxDay) {
             dayState.selectedItem = initialMaxDay
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt
index 1c029ab..40fc4f3 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/date/YearMonthPicker.kt
@@ -34,7 +34,7 @@ import kotlinx.datetime.number
  * @param modifier The modifier to be applied to the component.
  * @param pickerModifier The modifier to be applied to each picker.
  * @param state The state object to control the picker.
- * @param startLocalDate The initial date to display.
+ * @param startLocalDate Legacy initial date parameter. Prefer setting initial values in [state].
  * @param yearItems The list of year values to display.
  * @param monthItems The list of month values to display.
  * @param visibleItemsCount The number of items visible at once.
@@ -78,11 +78,11 @@ fun YearMonthPicker(
             modifier = Modifier.fillMaxWidth()
         ) {
 
-            val yearStartIndex = remember {
-                yearItems.indexOf(startLocalDate.year)
+            val yearStartIndex = remember(yearItems) {
+                yearItems.startIndexOf(state.selectedYear)
             }
-            val monthStartIndex = remember {
-                monthItems.indexOf(startLocalDate.month.number)
+            val monthStartIndex = remember(monthItems) {
+                monthItems.startIndexOf(state.selectedMonth)
             }
 
             Row(
@@ -133,6 +133,9 @@ fun YearMonthPicker(
     }
 }
 
+private fun <T> List<T>.startIndexOf(item: T): Int =
+    indexOf(item).takeIf { it >= 0 } ?: 0
+
 @Preview(name = "Default", group = "YearMonthPicker - Basic", showBackground = true)
 @Composable
 fun YearMonthPickerPreview() {
@@ -169,4 +172,4 @@ fun YearMonthPickerLargeTextPreview() {
         ),
         visibleItemsCount = 5
     )
-}
\ No newline at end of file
+}
diff --git a/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt b/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt
index 0ae773b..230f103 100644
--- a/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt
+++ b/datetimepicker/src/commonMain/kotlin/com/kez/picker/time/TimePicker.kt
@@ -38,7 +38,7 @@ import kotlinx.datetime.LocalDateTime
  * @param modifier The modifier to be applied to the component.
  * @param pickerModifier The modifier to be applied to each picker.
  * @param state The state object to control the picker.
- * @param startTime The initial time to display.
+ * @param startTime Legacy initial time parameter. Prefer setting initial values in [state].
  * @param minuteItems The list of minute values to display.
  * @param hourItems The list of hour values to display.
  * @param periodItems The list of period values to display.
@@ -87,25 +87,16 @@ fun TimePicker(
             modifier = Modifier.fillMaxWidth()
         ) {
 
-            val minuteStartIndex = remember {
-                minuteItems.indexOf(startTime.minute)
+            val minuteStartIndex = remember(minuteItems) {
+                minuteItems.startIndexOf(state.selectedMinute)
             }
 
-            val hourStartIndex = remember {
-                val startHour = when (state.timeFormat) {
-                    TimeFormat.HOUR_12 -> {
-                        val hour = startTime.hour % 12
-                        if (hour == 0) 12 else hour
-                    }
-
-                    TimeFormat.HOUR_24 -> startTime.hour
-                }
-                hourItems.indexOf(startHour)
+            val hourStartIndex = remember(hourItems) {
+                hourItems.startIndexOf(state.selectedHour)
             }
 
-            val periodStartIndex = remember {
-                val period = if (startTime.hour >= 12) TimePeriod.PM else TimePeriod.AM
-                periodItems.indexOf(period)
+            val periodStartIndex = remember(periodItems) {
+                periodItems.startIndexOf(state.selectedPeriod)
             }
 
             Row(
@@ -177,6 +168,9 @@ fun TimePicker(
     }
 }
 
+private fun <T> List<T>.startIndexOf(item: T): Int =
+    indexOf(item).takeIf { it >= 0 } ?: 0
+
 @Preview(name = "24-Hour Format", group = "TimePicker - Formats", showBackground = true)
 @Composable
 fun TimePickerPreview24Hour() {
@@ -226,4 +220,4 @@ fun TimePickerLargeTextPreview() {
         ),
         visibleItemsCount = 5
     )
-}
\ No newline at end of file
+}
diff --git a/datetimepicker/src/commonTest/kotlin/com/kez/picker/PickerUtilsTest.kt b/datetimepicker/src/commonTest/kotlin/com/kez/picker/PickerUtilsTest.kt
index 765276d..549119a 100644
--- a/datetimepicker/src/commonTest/kotlin/com/kez/picker/PickerUtilsTest.kt
+++ b/datetimepicker/src/commonTest/kotlin/com/kez/picker/PickerUtilsTest.kt
@@ -123,9 +123,21 @@ class PickerUtilsTest {
     @Test
     fun startIndex_boundedMode_calculatesCorrectly() {
         val startIndex = 2
-        val expectedBoundedStart = startIndex + 1 // +1 for null padding
+        val expectedBoundedStart = startIndex
 
-        assertEquals(3, expectedBoundedStart)
+        assertEquals(2, expectedBoundedStart)
+    }
+
+    @Test
+    fun boundedMode_paddingMatchesVisibleItemsMiddle() {
+        val visibleItemsMiddle = 2 // for visibleItemsCount = 5
+        val items = listOf("A", "B", "C")
+        val adjustedItems = List(visibleItemsMiddle) { null } + items + List(visibleItemsMiddle) { null }
+
+        assertEquals(null, adjustedItems[0])
+        assertEquals(null, adjustedItems[1])
+        assertEquals("A", adjustedItems[visibleItemsMiddle])
+        assertEquals("C", adjustedItems[visibleItemsMiddle + items.lastIndex])
     }
 
     // ==================== Fraction Calculation Tests ====================
diff --git a/datetimepicker/src/commonTest/kotlin/com/kez/picker/date/DatePickerStateTest.kt b/datetimepicker/src/commonTest/kotlin/com/kez/picker/date/DatePickerStateTest.kt
index 0de6d63..449456c 100644
--- a/datetimepicker/src/commonTest/kotlin/com/kez/picker/date/DatePickerStateTest.kt
+++ b/datetimepicker/src/commonTest/kotlin/com/kez/picker/date/DatePickerStateTest.kt
@@ -1,8 +1,8 @@
 package com.kez.picker.date
 
-import com.kez.picker.DatePickerState
 import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
 
 class DatePickerStateTest {
 
@@ -62,6 +62,20 @@ class DatePickerStateTest {
         assertEquals(29, state.selectedDay)
     }
 
+    @Test
+    fun testInitialMonth_Throws_WhenOutOfRange() {
+        assertFailsWith<IllegalArgumentException> {
+            DatePickerState(initialYear = 2024, initialMonth = 13, initialDay = 1)
+        }
+    }
+
+    @Test
+    fun testInitialDay_Throws_WhenLessThanOne() {
+        assertFailsWith<IllegalArgumentException> {
+            DatePickerState(initialYear = 2024, initialMonth = 1, initialDay = 0)
+        }
+    }
+
     @Test
     fun testSelectedValues_MatchInitialValues() {
         val state = DatePickerState(initialYear = 2025, initialMonth = 6, initialDay = 15)
diff --git a/gradle.properties b/gradle.properties
index f369053..e7b955c 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -32,7 +32,7 @@ kotlin.daemon.jvmargs=-Xmx4g -Xms1g -XX:ReservedCodeCacheSize=512m
 # Project Information
 GROUP=io.github.kez-lab
 POM_ARTIFACT_ID=compose-date-time-picker
-VERSION_NAME=0.4.0
+VERSION_NAME=0.5.0
 
 POM_NAME=Compose-DateTimePicker
 POM_DESCRIPTION=Compose Multiplatform DateTimePicker library supporting Android, iOS, Desktop and Web
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/App.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/App.kt
index 7e4ade1..b094e0a 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/App.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/App.kt
@@ -47,12 +47,12 @@ fun App() {
                     onBackPressed = { handleNavigateBack(navController) }
                 )
             }
-            composable(Screen.DatePicker.route) {
+            composable(Screen.YearMonthPicker.route) {
                 YearMonthPickerSampleScreen(
                     onBackPressed = { handleNavigateBack(navController) }
                 )
             }
-            composable(Screen.DayPicker.route) {
+            composable(Screen.DatePicker.route) {
                 DatePickerSampleScreen(
                     onBackPressed = { handleNavigateBack(navController) }
                 )
@@ -69,4 +69,4 @@ fun App() {
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/navigation/Screen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/navigation/Screen.kt
index 9b32b6d..ad924e6 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/navigation/Screen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/navigation/Screen.kt
@@ -4,8 +4,8 @@ sealed class Screen(val route: String) {
     object Home : Screen("home")
     object Integrated : Screen("integrated")
     object TimePicker : Screen("time_picker")
+    object YearMonthPicker : Screen("year_month_picker")
     object DatePicker : Screen("date_picker")
-    object DayPicker : Screen("day_picker")
     object BottomSheet : Screen("bottom_sheet")
     object BackgroundStyle : Screen("background_style")
 }
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BackgroundStylePickerScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BackgroundStylePickerScreen.kt
index 8fe6c90..27b1f84 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BackgroundStylePickerScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BackgroundStylePickerScreen.kt
@@ -30,6 +30,7 @@ import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import com.kez.picker.PickerDefaults
 import com.kez.picker.date.YearMonthPicker
 import com.kez.picker.rememberTimePickerState
 import com.kez.picker.rememberYearMonthPickerState
@@ -87,7 +88,7 @@ internal fun BackgroundStylePickerScreen(
                         )
                     }
                 },
-                colors = TopAppBarDefaults.centerAlignedTopAppBarColors(containerColor = Color.Transparent)
+                colors = TopAppBarDefaults.topAppBarColors(containerColor = Color.Transparent)
             )
         },
         containerColor = MaterialTheme.colorScheme.background
@@ -125,17 +126,21 @@ internal fun BackgroundStylePickerScreen(
                 ) {
                     YearMonthPicker(
                         state = yearMonthState,
-                        textStyle = TextStyle(
-                            fontSize = 18.sp,
-                            color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f)
-                        ),
-                        selectedTextStyle = TextStyle(
-                            fontSize = 22.sp,
-                            color = MaterialTheme.colorScheme.primary,
-                            fontWeight = FontWeight.Bold
+                        textStyles = PickerDefaults.textStyles(
+                            textStyle = TextStyle(
+                                fontSize = 18.sp
+                            ),
+                            selectedTextStyle = TextStyle(
+                                fontSize = 22.sp,
+                                fontWeight = FontWeight.Bold
+                            )
                         ),
                         isDividerVisible = false,
-                        selectedItemBackgroundColor = MaterialTheme.colorScheme.primaryContainer
+                        colors = PickerDefaults.colors(
+                            textColor = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f),
+                            selectedTextColor = MaterialTheme.colorScheme.primary,
+                            selectedItemBackgroundColor = MaterialTheme.colorScheme.primaryContainer
+                        )
                     )
                 }
             }
@@ -158,17 +163,21 @@ internal fun BackgroundStylePickerScreen(
                 ) {
                     TimePicker(
                         state = timeState,
-                        textStyle = TextStyle(
-                            fontSize = 18.sp,
-                            color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f)
-                        ),
-                        selectedTextStyle = TextStyle(
-                            fontSize = 22.sp,
-                            color = MaterialTheme.colorScheme.primary,
-                            fontWeight = FontWeight.Bold
+                        textStyles = PickerDefaults.textStyles(
+                            textStyle = TextStyle(
+                                fontSize = 18.sp
+                            ),
+                            selectedTextStyle = TextStyle(
+                                fontSize = 22.sp,
+                                fontWeight = FontWeight.Bold
+                            )
                         ),
                         isDividerVisible = false,
-                        selectedItemBackgroundColor = MaterialTheme.colorScheme.primaryContainer
+                        colors = PickerDefaults.colors(
+                            textColor = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f),
+                            selectedTextColor = MaterialTheme.colorScheme.primary,
+                            selectedItemBackgroundColor = MaterialTheme.colorScheme.primaryContainer
+                        )
                     )
                 }
             }
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BottomSheetSampleScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BottomSheetSampleScreen.kt
index bb7ed63..8fd7c5c 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BottomSheetSampleScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/BottomSheetSampleScreen.kt
@@ -36,6 +36,7 @@ import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import com.kez.picker.PickerDefaults
 import com.kez.picker.date.YearMonthPicker
 import com.kez.picker.rememberTimePickerState
 import com.kez.picker.rememberYearMonthPickerState
@@ -247,16 +248,20 @@ internal fun BottomSheetSampleScreen(
                     ) {
                         YearMonthPicker(
                             state = yearMonthState,
-                            textStyle = TextStyle(
-                                fontSize = 18.sp,
-                                color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f)
+                            textStyles = PickerDefaults.textStyles(
+                                textStyle = TextStyle(
+                                    fontSize = 18.sp
+                                ),
+                                selectedTextStyle = TextStyle(
+                                    fontSize = 22.sp,
+                                    fontWeight = FontWeight.Bold
+                                )
                             ),
-                            selectedTextStyle = TextStyle(
-                                fontSize = 22.sp,
-                                color = MaterialTheme.colorScheme.primary,
-                                fontWeight = FontWeight.Bold
-                            ),
-                            dividerColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.2f)
+                            colors = PickerDefaults.colors(
+                                textColor = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f),
+                                selectedTextColor = MaterialTheme.colorScheme.primary,
+                                dividerColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.2f)
+                            )
                         )
                     }
 
@@ -311,16 +316,20 @@ internal fun BottomSheetSampleScreen(
                     ) {
                         TimePicker(
                             state = timeState,
-                            textStyle = TextStyle(
-                                fontSize = 18.sp,
-                                color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f)
+                            textStyles = PickerDefaults.textStyles(
+                                textStyle = TextStyle(
+                                    fontSize = 18.sp
+                                ),
+                                selectedTextStyle = TextStyle(
+                                    fontSize = 22.sp,
+                                    fontWeight = FontWeight.Bold
+                                )
                             ),
-                            selectedTextStyle = TextStyle(
-                                fontSize = 22.sp,
-                                color = MaterialTheme.colorScheme.primary,
-                                fontWeight = FontWeight.Bold
-                            ),
-                            dividerColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.2f)
+                            colors = PickerDefaults.colors(
+                                textColor = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f),
+                                selectedTextColor = MaterialTheme.colorScheme.primary,
+                                dividerColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.2f)
+                            )
                         )
                     }
 
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/DatePickerSampleScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/DatePickerSampleScreen.kt
index 510fff3..a3c3243 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/DatePickerSampleScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/DatePickerSampleScreen.kt
@@ -27,8 +27,9 @@ import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import com.kez.picker.PickerDefaults
 import com.kez.picker.date.DatePicker
-import com.kez.picker.rememberDatePickerState
+import com.kez.picker.date.rememberDatePickerState
 import compose.icons.FeatherIcons
 import compose.icons.feathericons.ArrowLeft
 import compose.icons.feathericons.Calendar
@@ -75,13 +76,17 @@ fun DatePickerSampleScreen(
                 DatePicker(
                     state = state,
                     visibleItemsCount = 3,
-                    textStyle = MaterialTheme.typography.bodyLarge,
-                    selectedTextStyle = TextStyle(
-                        fontSize = 22.sp,
-                        color = MaterialTheme.colorScheme.primary,
-                        fontWeight = FontWeight.Bold
+                    textStyles = PickerDefaults.textStyles(
+                        textStyle = MaterialTheme.typography.bodyLarge,
+                        selectedTextStyle = TextStyle(
+                            fontSize = 22.sp,
+                            fontWeight = FontWeight.Bold
+                        )
                     ),
-                    dividerColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.5f)
+                    colors = PickerDefaults.colors(
+                        selectedTextColor = MaterialTheme.colorScheme.primary,
+                        dividerColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.5f)
+                    )
                 )
             }
 
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/HomeScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/HomeScreen.kt
index fbcfefd..a571adb 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/HomeScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/HomeScreen.kt
@@ -50,7 +50,7 @@ internal fun HomeScreen(navController: NavController) {
                         fontWeight = FontWeight.Bold
                     )
                 },
-                colors = TopAppBarDefaults.centerAlignedTopAppBarColors(
+                colors = TopAppBarDefaults.topAppBarColors(
                     containerColor = Color.Transparent
                 )
             )
@@ -82,15 +82,15 @@ internal fun HomeScreen(navController: NavController) {
                     title = "YearMonthPicker Sample",
                     description = "Standalone YearMonthPicker component",
                     icon = FeatherIcons.Calendar,
-                    onClick = { navController.navigate(Screen.DatePicker.route) }
+                    onClick = { navController.navigate(Screen.YearMonthPicker.route) }
                 )
             }
             item {
                 MenuListItem(
-                    title = "DayPicker Sample",
+                    title = "DatePicker Sample",
                     description = "Full DatePicker (Year, Month, Day)",
                     icon = FeatherIcons.Calendar,
-                    onClick = { navController.navigate(Screen.DayPicker.route) }
+                    onClick = { navController.navigate(Screen.DatePicker.route) }
                 )
             }
             item {
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/IntegratedPickerScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/IntegratedPickerScreen.kt
index 409c585..954d17d 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/IntegratedPickerScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/IntegratedPickerScreen.kt
@@ -30,9 +30,9 @@ import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.PrimaryTabRow
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Tab
-import androidx.compose.material3.TabRow
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
@@ -49,6 +49,7 @@ import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import com.kez.picker.PickerDefaults
 import com.kez.picker.date.YearMonthPicker
 import com.kez.picker.rememberTimePickerState
 import com.kez.picker.rememberYearMonthPickerState
@@ -113,7 +114,7 @@ internal fun IntegratedPickerScreen(
                         )
                     }
                 },
-                colors = TopAppBarDefaults.centerAlignedTopAppBarColors(containerColor = Color.Transparent)
+                colors = TopAppBarDefaults.topAppBarColors(containerColor = Color.Transparent)
             )
         },
         containerColor = MaterialTheme.colorScheme.background
@@ -134,7 +135,7 @@ internal fun IntegratedPickerScreen(
                 colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surface)
             ) {
                 Column(horizontalAlignment = Alignment.CenterHorizontally) {
-                    TabRow(
+                    PrimaryTabRow(
                         selectedTabIndex = selectedTabIndex,
                         containerColor = MaterialTheme.colorScheme.surface,
                         contentColor = MaterialTheme.colorScheme.primary,
@@ -172,30 +173,38 @@ internal fun IntegratedPickerScreen(
                             if (tabIndex == 0) {
                                 YearMonthPicker(
                                     state = yearMonthState,
-                                    textStyle = TextStyle(
-                                        fontSize = 18.sp,
-                                        color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f)
+                                    textStyles = PickerDefaults.textStyles(
+                                        textStyle = TextStyle(
+                                            fontSize = 18.sp
+                                        ),
+                                        selectedTextStyle = TextStyle(
+                                            fontSize = 22.sp,
+                                            fontWeight = FontWeight.Bold
+                                        )
                                     ),
-                                    selectedTextStyle = TextStyle(
-                                        fontSize = 22.sp,
-                                        color = MaterialTheme.colorScheme.primary,
-                                        fontWeight = FontWeight.Bold
-                                    ),
-                                    dividerColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.2f)
+                                    colors = PickerDefaults.colors(
+                                        textColor = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f),
+                                        selectedTextColor = MaterialTheme.colorScheme.primary,
+                                        dividerColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.2f)
+                                    )
                                 )
                             } else {
                                 TimePicker(
                                     state = timeState,
-                                    textStyle = TextStyle(
-                                        fontSize = 18.sp,
-                                        color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f)
-                                    ),
-                                    selectedTextStyle = TextStyle(
-                                        fontSize = 22.sp,
-                                        color = MaterialTheme.colorScheme.primary,
-                                        fontWeight = FontWeight.Bold
+                                    textStyles = PickerDefaults.textStyles(
+                                        textStyle = TextStyle(
+                                            fontSize = 18.sp
+                                        ),
+                                        selectedTextStyle = TextStyle(
+                                            fontSize = 22.sp,
+                                            fontWeight = FontWeight.Bold
+                                        )
                                     ),
-                                    dividerColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.2f)
+                                    colors = PickerDefaults.colors(
+                                        textColor = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f),
+                                        selectedTextColor = MaterialTheme.colorScheme.primary,
+                                        dividerColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.2f)
+                                    )
                                 )
                             }
                         }
@@ -282,4 +291,4 @@ internal fun SelectedDateTimeCard(date: String, time: String) {
 @Composable
 fun PreviewTimeCard() {
     IntegratedPickerScreen()
-}
\ No newline at end of file
+}
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/TimePickerSampleScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/TimePickerSampleScreen.kt
index e278567..852f40a 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/TimePickerSampleScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/TimePickerSampleScreen.kt
@@ -17,9 +17,9 @@ import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.PrimaryTabRow
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Tab
-import androidx.compose.material3.TabRow
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.derivedStateOf
@@ -151,7 +151,7 @@ internal fun TimePickerSampleScreen(
 
             Spacer(modifier = Modifier.height(24.dp))
 
-            TabRow(
+            PrimaryTabRow(
                 selectedTabIndex = selectedFormat,
                 modifier = Modifier.clip(RoundedCornerShape(16.dp))
             ) {
@@ -183,4 +183,4 @@ internal fun TimePickerSampleScreen(
 @Composable
 fun TimePickerSampleScreenPreview() {
     TimePickerSampleScreen()
-}
\ No newline at end of file
+}
diff --git a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/YearMonthPickerSampleScreen.kt b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/YearMonthPickerSampleScreen.kt
index f3394c1..71fb41d 100644
--- a/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/YearMonthPickerSampleScreen.kt
+++ b/sample/src/commonMain/kotlin/com/kez/picker/sample/ui/screen/YearMonthPickerSampleScreen.kt
@@ -68,7 +68,7 @@ internal fun YearMonthPickerSampleScreen(
                         Icon(FeatherIcons.ArrowLeft, contentDescription = "Back")
                     }
                 },
-                colors = TopAppBarDefaults.centerAlignedTopAppBarColors(
+                colors = TopAppBarDefaults.topAppBarColors(
                     containerColor = Color.Transparent
                 )
             )