Count on in minutes from the earlier time to the nearest hour.
Count on in hours to the hour nearest to the later time.
Count in minutes to reach the later time.
The gap from 9:25 PM to 10 PM is 35 min. The gap from 6 AM to 6:15 AM is 15 min. So far, that accounts for 35+15 = 50 min. The gap from 10 PM to midnight is 2 hours (10+2 = 12). Then the gap from midnight to 6 AM is 6 hours. So we have 2+6 = 8 hours. Add on the minute portion we computed to get 8 hours, 50 minutes.
