12 Hours ! There are 12 hours in the AM and 12 hours in the PM !
12 hours
12 hours
From midnight (am) to Noon (pm) is 12 hours.
2.5 hours
2 hours
3 hours
7 and a half hours
2 hours.
6 hours.
21 hours
There are 16 hours from 4 am to 8 pm. 4 am to 4 pm is 12 hours, then 4 pm to 8 pm is another 4 hours.