What can I use for time entry?

I am using Silverlight 4 and VS 2010. I am creating a timesheet type application, where the user enters the time they arrive and the time they leave. They need to be able to enter/choose the hours, minutes and AM/PM. Is there a premade control I can use for this? My goal is for the control to prevent incorrect entries so that my validation in the backend is not necessary. Thanks.

Any help would be great. Thanks.

Someone has to know something. I would think this is a pretty common thing.