matplotlib chart gives error

Greetings!

Kindly refer to chapter 11, point section 11.11 and fig 11.3. If I type the exact code, the plot gives date time data error.

Please suggest a way around. 

If I pass a column name to the ebola pandas data frame then it plots for that column. But there are too name columns to type in. But I do not know if this is the best way around.

Regards,
Andy

