Military Time Chart

Military time chart: all 24 hours

The 24-hour clock counts straight through from 0000 to 2359 without repeating a number, so there is no AM or PM to lose track of. Find the ordinary clock time in the left column and read across for the four-digit form and the way it is spoken aloud.

Midnight has two valid spellings and they mean different edges of the same instant. 0000 opens a day and 2400 closes the one before it. A shift written as 1600 to 2400 ends at midnight on the same calendar date it started; a shift written as 0000 to 0800 begins at midnight on the following date. Because that distinction gets misread, many units and hospitals avoid 2400 entirely and write 2359 for the last minute of the day.

Reading minutes on the 24-hour clock

The first two digits are the hour and the last two are the minutes. Nothing is ever separated by a colon in strict military usage, and nothing is ever rounded for you. So 1330 is half past one in the afternoon, 0745 is quarter to eight in the morning, and 2107 is 9:07 PM.

Spoken form changes as soon as minutes appear. The word "hundred" only belongs to an exact hour. At 1330 you say "thirteen thirty", not "thirteen hundred thirty". At 0605 you say "zero six zero five", digit by digit, because "six oh five" would be ambiguous over a radio. Anything on the hour keeps the "hundred" ending shown in the chart.

One habit makes a time card easier to total: keep all four digits, including leading zeros. Writing 800 instead of 0800 invites someone to read it as 8:00 PM on a busy roster. The military time card calculator accepts either form and echoes back the corrected four-digit value, which is a quick way to catch a transposed entry.

The subtract 12 rule

Converting an afternoon time to the familiar clock takes one subtraction. If the hour digits are 13 or higher, subtract 12 and add PM. If they are 12, the time is already noon plus minutes, so keep 12 and add PM. If they are 01 through 11, drop the leading zero and add AM. If they are 00, the hour is 12 AM.

1. 1830 has an hour of 18. Since 18 is 13 or higher, 18 minus 12 is 6, giving 6:30 PM.
2. 1215 has an hour of 12, so it stays at 12 and becomes 12:15 PM.
3. 0420 has an hour of 04, so the zero drops and it becomes 4:20 AM.
4. 0015 has an hour of 00, which is the midnight hour, so it becomes 12:15 AM.

Going the other way, add 12 to any PM hour except 12 itself. Duration is easier still, because there is no AM to PM boundary to trip over. A shift running 0545 to 1415 spans 8 hours 30 minutes: the hour digits go from 5 to 14, which is 9 hours to 1445, and 1415 falls 30 minutes short of that. Written as decimal hours that is 8.50, the figure payroll wants. The hours calculator will do the subtraction from either format, and the minutes to decimal hours chart covers the conversion at the end.

Time zones and Zulu time

Anywhere a schedule crosses regions, the four digits pick up a letter. That letter names the zone. Z, spoken "Zulu", is Coordinated Universal Time, the reference every other zone is measured from. A message timed 1400Z happened at fourteen hundred UTC no matter who reads it.

US zones carry their own letters: Eastern Standard Time is R, "Romeo", at UTC minus 5, and Pacific Standard Time is U, "Uniform", at UTC minus 8. To convert 0900R to Zulu you add the five hours you are behind, giving 1400Z. Daylight saving shifts the letter rather than the rule, so Eastern Daylight Time becomes Q, "Quebec", at UTC minus 4. Civilian schedules rarely need the letters, but flight crews, dispatchers and anyone logging incidents across states will see them, and dropping the suffix is how two people end up an hour apart on the same call.

Frequently asked questions