There are 8 hours from 6 PM to 2 AM. This includes the hours from 6 PM to midnight (6 hours) and then from midnight to 2 AM (2 hours).
From 2pm to 6pm is 4 hours. From 2am to 6pm is 16 hours.
10 hours
24 hours
48 hours.
15
It's 120 hours between 6pm Thursday until the following Tuesday at 6pm
From 8:15am to 6pm is 9 hours and 45 minutes.
72 hrs
9 hours
13 hours
11 hours
Four hours exactly.