8:30am to 2pm is 5.5hours (5 hours 30 mins)
8 hours.
Nine hours.
840
Nine and a half hours.
4.5 hours
3am to 2pm is 11 hours.
ten and a half
3am to 2pm is 11 hours.
There are 7 hours between 7 am to 2pm
8:30am to noon is 3.5 hours.
It is (8.5 + 24k) hours where k is an integer.
There are 17 hours between 9pm and 2pm the following day.