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
| 2PM to 9AM | 5PM to 6AM | 5AM to 10AM |
| 6PM to 9AM | 1AM to 5PM | 6AM to 3PM |
| 5PM to 1AM | 9PM to 10AM | 6AM to 9PM |
| 12AM to 2AM | 8AM to 4AM | 9PM to 5PM |
| 1AM to 9PM | 12PM to 7AM | 12PM to 5AM |
| 12PM to 12AM | 4AM to 2AM | 8AM to 9AM |
