Adding 1 day to my time

Adding 1 day to my time

I have kind of an odd situation, but here goes. Im trying to tell if one
time is between two others. I got that working. The problem is, the second
time is going to be in the next day. So for example The first time will be
8 pm, and the second time will be 8 am. And the problem is when I compare
the two times, the computer thinks that the 8am is before the 8 pm. So
this is my main question. How coan I make it so that the second day is a
day after the first, or tomorrow in a sense. like if today is the first,
the first time would be 8 pm the first, but the second time would be 8 am
the second.