What “military time” actually means
Military time is just the 24-hour clock used by every country except the US, with a few formatting tweaks (no colon in some military and aviation contexts: 1430 instead of 14:30). The hours run 00 through 23, so 1:00 PM becomes 13:00 and midnight is either 0000 or 2400 depending on convention.
The advantage: there’s no AM/PM ambiguity, which matters in hospitals (a medication ordered for “12:00” is dangerous), aviation (controllers and pilots must agree on the same minute worldwide), and global business (a meeting at “13:00 UTC” is unambiguous).
Quick conversion rules
- Midnight — 12:00 AM = 00:00 (zero hundred). Note: 24:00 is sometimes used to mean “end of day” (one second before midnight starts the next day).
- Morning (1 AM–11 AM) — same number, just zero-padded: 7:00 AM = 07:00.
- Noon — 12:00 PM = 12:00 (twelve hundred).
- Afternoon & evening (1 PM–11 PM) — add 12: 3:00 PM = 15:00, 9:30 PM = 21:30.
The decimal column
Decimal hours are the same conversion as anywhere else on this site: hours plus minutes ÷ 60. 13:30 = 13.5. 14:45 = 14.75. 23:15 = 23.25.
When is decimal-of-day useful? It’s rare in scheduling, but extremely useful for duration math: if a flight departs at 14:30 (14.5) and arrives at 17:15 (17.25), the duration is 17.25 − 14.5 = 2.75 hours = 2 h 45 m. The same trick works on timesheets when you don’t want to deal with HH:MM subtraction (which has those pesky 60-minute borrows).
Reference chart
| 24-hour | 12-hour | Decimal |
|---|---|---|
| 00:00 | 12:00 AM | 0.00 |
| 03:00 | 3:00 AM | 3.00 |
| 06:30 | 6:30 AM | 6.50 |
| 09:15 | 9:15 AM | 9.25 |
| 12:00 | 12:00 PM (noon) | 12.00 |
| 13:00 | 1:00 PM | 13.00 |
| 14:30 | 2:30 PM | 14.50 |
| 15:45 | 3:45 PM | 15.75 |
| 17:00 | 5:00 PM | 17.00 |
| 18:15 | 6:15 PM | 18.25 |
| 20:00 | 8:00 PM | 20.00 |
| 21:30 | 9:30 PM | 21.50 |
| 22:45 | 10:45 PM | 22.75 |
| 23:59 | 11:59 PM | 23.98 |
Frequently asked questions
What is 1500 in regular time?
1500 (15:00) = 3:00 PM. Subtract 12 from any military hour over 12:59 to get the PM number.
What is 0030 hours?
0030 = 12:30 AM (early morning). For times between midnight and 1 AM, the 12-hour version uses “12:… AM” rather than “0:…” — a quirk of the 12-hour system.
Is 24:00 the same as 00:00?
They refer to the same instant (midnight) but conventions differ: 24:00 typically means “end of today” while 00:00 means “start of tomorrow.” ISO 8601 prefers 00:00. Both are accepted in this calculator.
Why does Europe use 24-hour time?
Most European languages adopted the 24-hour clock for scheduling because it removes ambiguity. Spoken time often still uses 12-hour conventions in casual conversation.
