Quick answer
In 24-hour time, 00:00 is midnight at the start of the day and 12:00 is noon. For readings from 13:00 to 23:59, subtract 12 from the hour and use p.m.
Step by step
- For 00:xx, replace the hour with 12 and use a.m. For 01:xx through 11:xx, keep the hour and use a.m.
- For 12:xx, keep the hour and use p.m. For 13:xx through 23:xx, subtract 12 and use p.m.
- In reverse, change 12 a.m. to 00 and keep 12 p.m. as 12. Add 12 to other p.m. hours and leave other a.m. hours alone.
Worked examples
Midnight and noon
00:15 is 12:15 a.m. and 12:15 is 12:15 p.m.
Afternoon
16:33 is 4:33 p.m.
Early morning
7:05 a.m. becomes 07:05. Keep the minute digits in every conversion.
Quick reference
| 24-hour | 12-hour |
|---|---|
| 00:00 | 12:00 a.m. (midnight) |
| 06:30 | 6:30 a.m. |
| 12:00 | 12:00 p.m. (noon) |
| 18:30 | 6:30 p.m. |
| 23:59 | 11:59 p.m. |
What to check
When a schedule crosses midnight, write the date next to the time. The clock format by itself cannot distinguish which day you mean.
Related guides
See the calculation methodology or report an error.