Military time converter

How the 24-hour clock works

Military time counts the hours of the day straight through from 00 to 23 instead of starting again at 12. The day begins at 0000, midnight, and ends at 2359, one minute before the next midnight. It’s written with four digits: the first two are the hour and the last two are the minutes, so 0615 is a quarter past six in the morning and 1815 is a quarter past six in the evening. Because every hour has its own number, AM and PM aren’t needed.

Morning times look almost the same in both systems, with a zero in front: 9:30 AM is 0930. After noon, the hours keep counting: 1:00 PM is 1300, 6:00 PM is 1800 and 11:00 PM is 2300. That’s the whole trick. To go from military to standard time, subtract 12 from any hour of 13 or more and add PM. To go the other way, add 12 to any PM hour from 1 PM on.

Midnight and noon

The two 12 o’clocks cause most mistakes. Noon is 1200, and it’s the one PM hour you don’t add 12 to: 12:45 PM is 1245. Midnight is hour zero, so 12:45 AM is 0045. Midnight can also be written 2400 when it marks the end of a day. A shift from 1600 to 2400 ends at the same moment as one from 1600 to 0000 the next day; 2400 just makes it clear which day is meant. To avoid any doubt, some schedules and contracts use 2359 or 0001 instead.

Common conversions

Saying it aloud

In the US military, a time is read as two pairs of numbers followed by “hours”. 1730 is “seventeen thirty hours”, 2145 is “twenty-one forty-five hours”, and on the hour you say “hundred”: 1400 is “fourteen hundred hours”. A leading zero is spoken, so 0600 is “zero six hundred hours”, and 0005 is “zero zero zero five hours”. In everyday speech many people say “oh” instead of “zero” (“oh six hundred”) and drop the word “hours”.

Who uses military time

The armed forces use it because orders and reports can’t afford an AM/PM mix-up, and they often add a time zone letter, such as Z (“Zulu”) for Coordinated Universal Time. Hospitals and nursing homes commonly chart medication and observations in 24-hour time for the same reason. Pilots and air traffic control work in UTC on a 24-hour clock, and police, fire and ambulance dispatch log calls the same way. Outside the US and a few other countries, the 24-hour clock is simply everyday time, written with a colon (17:30) on timetables, tickets and phones.

Need the whole day on paper? The printable military time chart fits every hour and a minutes table on one page. To add up shifts written in 24-hour time, use the hours calculator for one shift or the time card calculator for a whole week. To add or subtract lengths of time, try the time calculator.