Military Time Converter

Military time counts the hours of the day from 00 to 23 and writes them as four digits with no colon: 0630, 1200, 1845. The minutes never change. Only the hour does, and only in three cases:

• 1300 to 2359: subtract 12 and add PM. 1845 → 18 − 12 = 6 → 6:45 PM.
• 0000 to 0059: the hour is 12 AM. 0015 → 12:15 AM.
• PM times from 1:00 to 11:59: add 12. 7:05 PM → 19 → 1905.

Morning times keep their hour with a leading zero (9:30 AM → 0930), and 12:00 PM to 12:59 PM stay as 1200 to 1259. Strictly, the US military writes times without a colon (1845), while civilian 24-hour clocks in most of the world use one (18:45). The time is the same.

Say the four digits as two pairs, then "hours":

• On the hour, say "hundred": 0600 is "zero six hundred hours", 1400 is "fourteen hundred hours".
• Say leading zeros: 0730 is "zero seven thirty hours". Many people say "oh" instead of "zero" ("oh-seven-thirty"), which is common in speech but less formal.
• Minutes under ten keep their zero: 1905 is "nineteen zero five hours".
• Midnight: 0000 is "zero hundred hours".

Avoid "eighteen hundred forty-five". It mixes the two styles and can be misheard on a radio.

Midnight has two military spellings. 0000 is the first minute of a day and 2400 is the end of the previous one, so "on duty 1600 to 2400 on 3 June" finishes at the same instant as 0000 on 4 June. Clocks never display 2400; it only appears in schedules.

Because 12 AM and 12 PM are so often confused, many organisations avoid midnight altogether: a deadline of 2359 clearly means the end of the stated day, and a start of 0001 clearly means its beginning. If you write instructions for others, that is the safest choice.

Military and aviation messages add a letter to say which time zone a time is in. Z (Zulu) is Coordinated Universal Time (UTC), so 1300Z is 1300 UTC everywhere in the world. Letters A to M (skipping J) are zones east of UTC, one hour apart, and N to Y are zones west. J (Juliett) means local time wherever the reader is.

The letters describe a fixed offset, not a place, so a base switches letters when daylight saving starts: US Eastern is R (UTC−5) in winter and Q (UTC−4) in summer.

Military messages put the date, time and zone into one string called a date-time group: day, hours, minutes, zone letter, month, year. For example, 151300Z OCT 26 reads as: