In this post, David Anson discusses the
Date and Time picker for
Windows Phone 7.
Source: Delay's Blog
As with the rest of the Phone Toolkit, our primary goal was to make it easy for developers to match the core Windows Phone 7 experience in their own applications. Toward that end, adding an instance of DatePicker or TimePicker to a page gives the same "small button expands to full-page date/time picker with infinite scrolly thingies" experience that's found in the core Settings, Calendar, and Alarms applications. But sometimes you want to do things a little differently, and maybe you've got a date/time picking interface in mind that's more relevant to your scenario...