Military Time: How to Read the 24-Hour Clock

Military time — also called the 24-hour clock — is used by the military, hospitals, airlines, and most of the world outside the US. If you've ever looked at a schedule and wondered whether 15:30 is AM or PM, this guide is for you.

The Basic Rule

Military time runs from 00:00 (midnight) to 23:59 (one minute before the next midnight). There's no AM or PM. The numbers just keep going past 12.

The Trick: Just Add or Subtract 12

Converting between military and standard time is one simple rule:

• For times 00:00-12:00: Same as standard time (just remove the leading zero if you want). 09:00 = 9:00 AM.
• For times 13:00-23:59: Subtract 12 to get the PM hour. 15:00 - 12 = 3:00 PM.

That's it. No exceptions.

Why Use Military Time?

The main reason: it eliminates ambiguity. In standard time, "12:00" could be noon or midnight. "Meet me at 7" could be morning or evening. In military time, 07:00 and 19:00 are clearly different.

This matters in contexts where mistakes are costly:

• Hospitals: Giving medication at 18:00 instead of 06:00 could be dangerous
• Aviation: A 12-hour ambiguity in a flight plan could cause a collision
• Military operations: "Operation starts at 0400" leaves no room for confusion

How to Read It Out Loud

In the military, times are pronounced differently than you might expect:

• 0800 = "zero eight hundred" (not "eight hundred hours" — though "hours" is sometimes added)
• 1500 = "fifteen hundred"
• 0005 = "zero zero zero five"
• 2359 = "twenty-three fifty-nine"

You don't need to use this pronunciation in civilian life, but it helps to understand it when you hear it.

Who Uses the 24-Hour Clock?

Most of the world. The US, UK, Canada, Australia, Philippines, and a few other countries use the 12-hour clock in daily life. But even in those countries, the 24-hour clock is used in specific contexts:

• UK train schedules use 24-hour time
• Canadian French speakers commonly use 24-hour time
• Australian hospitals and emergency services use it
• Smartphones in most countries default to 24-hour display

Setting Your Phone to 24-Hour Time

If you want to get comfortable with military time, switch your phone to 24-hour format:

• iPhone: Settings → General → Date & Time → 24-Hour Time (toggle on)
• Android: Settings → System → Date & Time → Use 24-hour format

After a day or two, you'll stop converting in your head and just read 17:00 as "five o'clock." It's faster than the 12-hour system once you're used to it.

If you're scheduling something across time zones and want to avoid AM/PM confusion, our meeting planner shows times clearly for multiple cities.