Military Time Converter

The full 24-hour chart

Every whole hour, what it means on a 12-hour clock, and how it's spoken. For any minute other than the hour, keep the minutes exactly as they are — 1630 is 4:30 PM, 1647 is 4:47 PM. Minutes never change between the two systems.

The three rules

You don't need the chart once you know these.

• Morning (12:00 AM to 11:59 AM): drop the colon and the AM, then pad to four digits. 7:30 AM becomes 0730. Midnight hour times use 00, so 12:15 AM is 0015.
• Noon hour (12:00 PM to 12:59 PM): nothing changes but the format. 12:45 PM is 1245. This is the one PM hour you don't add 12 to.
• Afternoon and evening (1:00 PM to 11:59 PM): add 12 to the hour. 3 PM becomes 15, so 3:45 PM is 1545.

Going back the other way: if the first two digits are 12 or less, it's already the standard hour and it's AM (except 12, which is noon). If they're 13 or more, subtract 12 and it's PM. 2100 minus 12 is 9, so 2100 is 9:00 PM.

Is midnight 0000 or 2400?

Both, and the difference is which day you're counting toward.

0000 is the first minute of a day. 2400 is the last instant of the day before it. They mark the same point on the clock, but they belong to different dates — 2400 on Tuesday and 0000 on Wednesday are the same moment.

In practice, US military and most operational timekeeping runs 0000 through 2359 and avoids 2400 entirely, because a day that ends at 2359 and the next that starts at 0000 leaves no gap and no overlap. You'll still see 2400 in contexts where a period needs a closing boundary — a shift running 1600 to 2400, or a duty log covering 0000–2400. The international standard for timestamps, ISO 8601, permits 24:00 for exactly this purpose, as an end-of-day marker only.

How to say it

Written military time is always four digits with no colon and no word attached: 1500, not 15:00 and not "1500 hours." Spoken, the conventions are different.

• Whole hours take "hundred hours" — 1400 is "fourteen hundred hours." In casual operational speech the "hours" often gets dropped: "meet at fifteen hundred."
• Hours with minutes are said as two numbers, no "hundred" — 1545 is "fifteen forty-five," 0730 is "zero seven thirty."
• Leading zeros are spoken — 0700 is "zero seven hundred," not "seven hundred." Over a radio, a clipped first syllable shouldn't be able to turn one time into another.
• Midnight is usually "zero zero zero zero" or simply "midnight." 2400 is "twenty-four hundred hours."

Zulu time and UTC

Military time solves the AM/PM problem but not the time zone problem — 0800 in San Diego and 0800 in Norfolk are five hours apart. Zulu time solves that. It's Coordinated Universal Time written in the same four-digit format, with a Z on the end: 1400Z is the same instant everywhere on Earth.

The name comes from the NATO phonetic alphabet, where Z is "Zulu" — the suffix used on UTC timestamps. Aviation, weather services and international operations all run on it for the same reason: one timestamp that needs no interpretation.

UTC does not observe daylight saving, so the offset between Zulu and US local time changes twice a year:

To convert, subtract the offset from the Zulu time. 1800Z in Eastern Standard Time is 1800 − 5 = 1300, or 1:00 PM. In summer it's 1800 − 4 = 1400, or 2:00 PM. If subtracting takes you below 0000, add 24 and step back a day: 0300Z is 2200 the previous day on the East Coast in winter.

Who uses it

Beyond the armed forces, the 24-hour clock is standard wherever an ambiguous timestamp would be dangerous. Aviation runs on Zulu time for flight plans, air traffic control and weather reports. Hospitals use it on medication schedules and charts, because handwritten "6 PM" and "6 AM" look alike and 1800 and 0600 do not. Fire, EMS and police log incidents in 24-hour time so that records from different agencies line up. Weather services, maritime navigation and international broadcasting use it for the same reason.

Common questions

What is 1600 hours?

4:00 PM. Subtract 12 from 16. Spoken as "sixteen hundred hours."

What is 1800 in military time?

1800 is military time — it means 6:00 PM. Going the other way, 6:00 PM converts to 1800 by adding 12 to 6.

What time is 2100?

9:00 PM. Spoken as "twenty-one hundred hours."

Does military time use a colon?

No. Written properly it's four digits with no separator — 1545, not 15:45. The colon form is the 24-hour clock as used in most of the world, which is the same system written differently.

What comes after 2359?

0000, and it's the next day. There is no 2360 and no 2400 as a starting point.

Sources

• North Carolina Office of State Fire Marshal — Military Time. Conversion rules and the 24-hour cheat sheet used in emergency services training.
• NOAA Air Resources Laboratory — READY Tools: Time Conversion Table. UTC-to-US-time-zone offsets for standard and daylight saving time.
• ISO 8601 — date and time representation, including the treatment of 24:00 as an end-of-day boundary.

The chart on this page was generated from the conversion arithmetic rather than transcribed.