There are total 21 hours or 1260 minutes from 4am to 1am. In words, this duration is equal to twenty-one hours or one thousand two hundred sixty minutes.
How many hours from
| 11AM to 3PM | 9PM to 7PM | 6AM to 2PM |
| 7AM to 10AM | 10PM to 6AM | 3PM to 8AM |
| 5PM to 3AM | 7PM to 3PM | 5PM to 4AM |
| 8PM to 9PM | 7PM to 4PM | 11PM to 1AM |
| 8AM to 6AM | 2AM to 9PM | 7PM to 3AM |
| 9AM to 9PM | 10AM to 10PM | 1PM to 9AM |
