Roll Date If Time Entered Is After Midnight

Hi again,

 In ASP.net, is there any elegant way to handle a set of time inserts from a form when the 2nd time is past midnight?

Specifically, I have a form with 2 textboxes on it (startTime and endTime) that are set up to accept time values (using AJAX MaskedEditExtender for formatting/validation - pretty cool). This data is posted to a sub that enters the data into a table (T_Details). However, I've noticed that the data inserted as part of the record (SQL field is smalldatetime) doesn't take into account the fact that a time value past 23:59:59 in the "endTime" textbox is a time on the next day - it simply rolls to an A.M. date for the same day as the date for the pre-midnight value from the "startTime" textbox. 

I'm sure that I can simply do some conditional coding and modify the date if necessary but is there a better way to do it? Thanks as always...this forum is a great resource