I believe sanrajesh is asking if you can use the calendar date picker to select a time of day instead of dates. To the best of my knowledge, you cannot.
I solved my problem by using warrtalon's suggestion of just using a text box and formatting it for time (text box properties > Data type). I then added a screen tip from the properties Advanced tab to the box indicating to the user how to enter the time.
This seems to be working out pretty well. At least users are figuring it out so far.