9 am to 11 am is two hours.
20
11- 9 = 2, so 2 hours.
9am, 10am, 11am, 12pm, 1pm, 2pm, 3pm, 4pm, 5pm. 8 hours.
3
monday-thursday 11am - 9pm friday-saturday 11am-10pm sunday 9am-9pm
From 9:00 am on Saturday to 9:00 am on a Wednesday, is 96 + 168k hours where k is an integer.
If it's 9am then 11pm was 10 hours ago If it's 9pm then 11am was 10 hours ago
12 hours.
The plane takes off at 9am. 9am to 10am is one hour. 10am to 11am is one hour. 11am to noon is one hour. The plane arrives at London at noon.
From 9am to 6:30pm is 9 hours and 30 minutes.
21
15 minutes