-1 if t1 is shorter than t2.
0 if t1 is equal to t2.
1 if t1 is longer than t2.
TimeSpan.Compare(t1.TimeOfDay, t2.TimeOfDay)
DateTime t1 = DateTime.Parse("2012/12/12 15:00:00.000");
DateTime t2 = DateTime.Parse("2012/12/12 15:03:00.000");
if(t1.TimeOfDay > t2.TimeOfDay) {
//something
}
else {
//something else
}