If it's 9am then 11pm was 10 hours ago If it's 9pm then 11am was 10 hours ago
Friday 11pm to Monday 11pm is exactly 3 days or 72 hours.
12 hours.
There are 72 + 168n hours where n is an integer.
from 9am to 11pm
7 hours
21
From 9am to 6:30pm is 9 hours and 30 minutes.
6 hours
7
17 hours
15 hours