The rule
- From 00:00 to 00:59, add 12 and write AM (00:30 is 12:30 AM).
- From 01:00 to 11:59, keep the time and write AM.
- From 12:00 to 12:59, keep the time and write PM (noon).
- From 13:00 to 23:59, subtract 12 and write PM (17:45 is 5:45 PM).
Conversion chart
| 24-hour clock | 12-hour clock |
|---|---|
| 00:00 | 12:00 AM |
| 01:00 | 1:00 AM |
| 02:00 | 2:00 AM |
| 03:00 | 3:00 AM |
| 04:00 | 4:00 AM |
| 05:00 | 5:00 AM |
| 06:00 | 6:00 AM |
| 07:00 | 7:00 AM |
| 08:00 | 8:00 AM |
| 09:00 | 9:00 AM |
| 10:00 | 10:00 AM |
| 11:00 | 11:00 AM |
| 24-hour clock | 12-hour clock |
|---|---|
| 12:00 | 12:00 PM |
| 13:00 | 1:00 PM |
| 14:00 | 2:00 PM |
| 15:00 | 3:00 PM |
| 16:00 | 4:00 PM |
| 17:00 | 5:00 PM |
| 18:00 | 6:00 PM |
| 19:00 | 7:00 PM |
| 20:00 | 8:00 PM |
| 21:00 | 9:00 PM |
| 22:00 | 10:00 PM |
| 23:00 | 11:00 PM |
Working out durations
24-hour time makes durations easier: a train leaving at 21:40 and arriving at 06:15 the next day runs for (24:00 − 21:40) + 06:15 = 2 h 20 min + 6 h 15 min = 8 h 35 min.
Try it yourself. Get your own result in seconds with the free Hours Calculator.
Open the Hours CalculatorFrequently asked questions
What is 18:00 in 12-hour time?
6:00 PM.
Is 00:00 midnight or noon?
00:00 is midnight; 12:00 is noon.
More guides
Written and reviewed by the editorial team at Evavel Private Limited. Found an error? Email care@calculations.one.