Note: 10pm, 11pm, 12pm, 1am, 2am, 3am = 5 hours
Friday 11pm to Monday 11pm is exactly 3 days or 72 hours.
12pm to 7pm is a span of 7 hours.
3 hours between 12pm and 3pm
21
There are 72 + 168n hours where n is an integer.
12 hours
7 hours
6 hours.
20
2
-6