7 hours and 30 minutes
You can subtract the hours and the minutes separately.
The duration between 3:30 pm and 9:15 pm is 5 hours and 45 minutes.
The elapsed time is 4 hours and 53 minutes.
10:28 PM
23 hours and 38 minutes.
7 hours and 30 minutes
You can subtract the hours and the minutes separately.
3 hours and 30 minutes.
4 hours and 20 minutes.
6 hours and 30 minutes
4 hours and 15 minutes.
3 hours and 12 minutes.
5 hours and 30 minutes.
8 hours and 30 minutes.
The duration between 3:30 pm and 9:15 pm is 5 hours and 45 minutes.
It is (4+24k) hours and 49 minutes, where k is any integer.