i have a doubt in datetimepicker tool in c#

Question

hai friends

 i have a doubt in datetimepicker tool in c#.

 (ie) 1. i have to display remaining days in a selected date use only one datetimepicker.

for eg today date is 22-apr-2011. remaining days upto 31-mar-2012.

if it is jan, feb and mar it should display the days of current year 

for eg 12-jan-2011 remaining days upto 31-mar-2011.

2. display the days of current month using datetimepicker tool in c#.

eg. if i am selecting jan month, the textbox should tells days = 31