Actually you missed it... you posted in the VB6 area... you want the .NET area... I'll let someone know it needs to be moved.
At anyrate, the DTP has a .Value property that will get you the date selected.
Had this been really for VB6, I would have then pointed you at the DateDiff function... but that won't do any good.
In .Net, you can actually do it like this:
Code:
Dim date1 As Date = CDate("1/1/2009")
Dim date2 As Date = CDate("12/31/2009")
Dim diff As TimeSpan = date2.Subtract(date1)
The TimeSpan object will then contain all of the info you need. There are a number of properties in there that will return the difference in hours, minutes, days, months, weeks and so on, poke around, look it up on MSDN and see what fits for you.
-tg