World clocks & live time
24-hour military time clock
Unambiguous time, the way the military, pilots, and hospitals keep it. A live 0000–2359 clock with the spoken form, Zulu time, and a conversion chart.
Military and aviation time runs 0000–2359, avoiding AM/PM ambiguity. "Zulu" time is UTC — the shared reference used across zones.
How to use the 24-hour military time clock
Read the 24-hour clock
The live readout runs from 00:00 through 23:59. Midnight is 00:00, noon is 12:00, and the afternoon simply continues counting — 3pm is 15:00.
Convert in your head
For afternoon times, subtract twelve to get the 12-hour form: 18:30 is 6:30pm. Going the other way, add twelve to any pm time.
Use the conversion table
The full hour-by-hour mapping is listed, including how each hour is spoken aloud in military usage — "zero six hundred", "seventeen thirty".
Check other zones
The same 24-hour format is shown for other cities, which is how it is used in practice: an unambiguous time that survives being written down and read by someone in another country.
Why 24-hour time exists
The twelve-hour clock is ambiguous twice a day, and the ambiguity is worst exactly where it matters most. "12am" and "12pm" are so unreliable that style guides recommend writing "midnight" and "noon" instead — and a deadline of "12am Friday" is genuinely unclear about which end of Friday is meant. The 24-hour clock has no such case: 00:00 is the start of the day and 12:00 is the middle of it.
Militaries, aviation, medicine, rail and emergency services adopted it for the same reason: a written time must not need an accompanying explanation. Aviation goes a step further and works in a single zone — UTC, spoken as "Zulu" — so a flight plan crossing eight zones has one unambiguous set of times on it.
Military usage differs slightly from plain 24-hour civil time in how it is spoken and written. Colons are usually dropped (1730), leading zeros are always present (0600), and hours are read as "hundred": 0600 is "zero six hundred hours". Adding a zone letter — 1730Z for UTC — makes it fully unambiguous on paper.
Most of the world already writes time this way; the twelve-hour clock in writing is largely a United States, Canadian, Australian and British habit. If you are writing for an international audience, the 24-hour form removes an entire category of misunderstanding at no cost.
When you'd reach for it
Writing for a global team
Put 14:00 in the invite rather than 2:00 and the pm never gets lost in translation.
Aviation and maritime
Flight plans, logs and weather reports are all 24-hour, usually in UTC.
Healthcare records
Medication and observation times are written 24-hour precisely because a missed "pm" can be dangerous.
Rail and transit
Timetables outside North America are almost universally 24-hour.
Learning the format
A live clock plus the full table is the fastest way to stop converting consciously.
Log files and systems
Machine-written timestamps are 24-hour; reading them fluently makes debugging quicker.
Questions & answers
- How does military time work?
- It runs from 0000 (midnight) to 2359, with no AM or PM. 1:00 PM is 1300, 6:30 PM is 1830. After noon, add 12 to the hour.
- What is Zulu time?
- Zulu (Z) time is UTC — Coordinated Universal Time — used by the military, aviation, and shipping as a single global reference so everyone agrees on the moment regardless of local zone.
- Why say '1430' as 'one four three zero'?
- Reading each digit separately is the NATO phonetic convention; it's less error-prone than 'fourteen thirty' over noisy radio.