Like I said, this is an XY problem.
The X is checking the current time against a user-selected time to determine whether or not it is now time to do something.
The Y is formatting a pair of integers as a string in such-and-such a format.
Working with times is a rabbit hole. Working with strings is another rabbit hole.
If you are going to go down a rabbit hole, at least make sure it's the right rabbit hole for the particular rabbit you're hunting.