Sixty (60), same as a civilian hour.
One hour = 60 minutes;Two hours = 2*60 =120 minutes;Three hours = 3*60 = 180 minutes; ...
24.62 minutes is about 41% of an hour, so about two fifths of an hour.
There are 9 hours and 18 minutes in 558 minutes.
7 hours, 44 minutes.
There are 9 hours and 50 minutes in 590 minutes.