9 hours.
10 hours and 15 minutes.
10.5 + 24*k hours where k is any integer.
If they're both on the same date, then they mark a period of 21/2 hours.
There are 8.5 hours. * hours and 30 minutes
12 hours
7
6
Ten hours.
8 hours.
9 hours.
9 hours.
8.5
10 hours and 15 minutes.
10 hours and 45 minutes.
12 hours 30 minutes.
7 and a half hours