Military Time Conversion Guide (24-Hour Clock Explained)

Military time, more accurately called the 24-hour clock, numbers the hours of the day from 00 to 23 instead of splitting them into two 12-hour AM and PM cycles. It's the standard format used by militaries, hospitals, airlines, train schedules, and most of the world outside the United States.

The basic conversion rule

For times from midnight to noon, 24-hour time matches 12-hour AM time almost exactly, just written with a leading zero and no colon-separated period marker (0800 instead of 8:00 AM). For times after noon, subtract 12 from the 24-hour value to get the 12-hour PM equivalent: 1500 becomes 3:00 PM, and 2130 becomes 9:30 PM.

Reference table

Why it's called "military" time in some countries

In the United States, Canada, and a handful of other countries, the 24-hour clock is strongly associated with military, aviation, and medical use because it removes any ambiguity about whether a time is AM or PM — a critical safety feature when scheduling operations, medications, or flights across time zones. In most of the rest of the world, the same format is simply the everyday standard for train timetables, TV guides, and daily conversation.

Common mistakes to avoid

The most frequent error is forgetting that 12:00 in 24-hour time is noon, not midnight — midnight is 00:00. Another common slip is misreading times just after noon, like assuming 1300 means 1:00 AM instead of 1:00 PM.