24 Hour Clock
The 24 hour clock runs from 00:00 at midnight through 23:59. Military time writes those same hours as four digits: 0000 through 2359, with no AM or PM.
From 0100 through 1159 the hour matches a 12-hour morning. 1200 is noon. From 1300 through 2359, subtract 12 and mark the time PM. A full minute-by-minute grid is on the military time chart.
| Military | 24 hour clock | Standard | Say it |
|---|---|---|---|
| 0000 | 00:00 | 12:00 AM | zero hundred |
| 0100 | 01:00 | 1:00 AM | one hundred |
| 0200 | 02:00 | 2:00 AM | two hundred |
| 0300 | 03:00 | 3:00 AM | three hundred |
| 0400 | 04:00 | 4:00 AM | four hundred |
| 0500 | 05:00 | 5:00 AM | five hundred |
| 0600 | 06:00 | 6:00 AM | six hundred |
| 0700 | 07:00 | 7:00 AM | seven hundred |
| 0800 | 08:00 | 8:00 AM | eight hundred |
| 0900 | 09:00 | 9:00 AM | nine hundred |
| 1000 | 10:00 | 10:00 AM | ten hundred |
| 1100 | 11:00 | 11:00 AM | eleven hundred |
| 1200 | 12:00 | 12:00 PM | twelve hundred |
| 1300 | 13:00 | 1:00 PM | thirteen hundred |
| 1400 | 14:00 | 2:00 PM | fourteen hundred |
| 1500 | 15:00 | 3:00 PM | fifteen hundred |
| 1600 | 16:00 | 4:00 PM | sixteen hundred |
| 1700 | 17:00 | 5:00 PM | seventeen hundred |
| 1800 | 18:00 | 6:00 PM | eighteen hundred |
| 1900 | 19:00 | 7:00 PM | nineteen hundred |
| 2000 | 20:00 | 8:00 PM | twenty hundred |
| 2100 | 21:00 | 9:00 PM | twenty-one hundred |
| 2200 | 22:00 | 10:00 PM | twenty-two hundred |
| 2300 | 23:00 | 11:00 PM | twenty-three hundred |
How to read a 24 hour clock
The first two digits are the hour. The last two are the minutes, 00 through 59, same as any other clock. 1730 is 17:30, which is 5:30 PM. Morning hours keep a leading zero: 0900, not 900.
Schedules sometimes print 2400 for midnight at the end of a listed day. That is the same clock face as 0000, which opens the next day. This table starts at 0000.
Where people use it
Hospitals, aviation, and duty rosters use the 24 hour clock so a dropped AM or PM cannot move a time by twelve hours. Visitor calendars often keep 5:00 PM. Mixed rooms write both once: 1700 / 5:00 PM.
Military time is a digit style, not a time zone. 1700 in New York and 1700 in Los Angeles are each 5:00 PM on the local clock. Zulu, or a trailing Z, names Coordinated Universal Time.
Keep going
Questions
What is the 24 hour clock?
The 24 hour clock numbers the day from 00:00 at midnight through 23:59. It does not use AM or PM.
Is the 24 hour clock the same as military time?
Military time is the 24 hour clock written as four digits, with no colon. 17:00 and 1700 are both 5:00 PM.
How do I convert 5:00 PM to the 24 hour clock?
Add 12 to a PM hour that is not noon. 5:00 PM is 17:00, written 1700 in military time. 12:00 PM stays 12:00.
What is 00:00?
00:00 is midnight at the start of the day, the same moment as 12:00 AM and 0000.
Is 24:00 a real hour?
24:00 is another way to write midnight at the end of a listed day. The next day starts at 00:00. This chart uses 0000 for that moment.
How do you say 1700?
Say seventeen hundred. On the hour, say the hour and then hundred, not o'clock.
Why do hospitals use a 24 hour clock?
A 24 hour clock keeps 7:00 AM and 7:00 PM from looking like the same time on a chart. 0700 and 1900 cannot be swapped by dropping AM or PM.