Military Time Converter

How to use the military time converter

1. Type an ordinary clock time into the 12-hour field, including AM or PM, for example 2:30 PM.
2. Read the four-digit equivalent that appears straight away, in this case 1430.
3. To translate a log entry the other way, type the four digits into the 24-hour field, such as 0745.
4. Read the AM or PM version it returns, here 7:45 AM.
5. Scroll to the 24-row chart below the converter for the whole day at once.

Reading 1300 through 2359

The 24-hour clock counts straight through the day instead of restarting after noon, so the afternoon and evening carry the numbers 13 through 23. Every one of them is the familiar hour plus twelve. To read a four-digit time above 1259, subtract 12 from the first two digits and add PM: 1515 becomes 15 minus 12 equals 3, so 3:15 PM. 2245 becomes 22 minus 12 equals 10, so 10:45 PM. The last two digits are already minutes and never change.

Going the other way you add instead. A 3:15 PM start is 3 plus 12 equals 15, written 1515. Morning times need no arithmetic at all, only a leading zero to keep the figure four digits wide: 7:45 AM is 0745 and 9:05 AM is 0905. Noon is the one hour that sits still, because 12 PM is already the twelfth hour of the day and stays 1200.

Two formatting habits come with the notation. There is no colon, and there is no AM or PM, because the number itself tells you which half of the day you are in. A time is always four digits, so 6 in the morning is 0600 and never 600. The full hour-by-hour listing sits in the chart on this page, and a printable version lives on the military time chart.

Midnight: 0000 or 2400

Midnight is the only ambiguous point, and both forms are in use. 0000 marks the instant a new day begins, so a shift starting just after midnight is logged at 0000 or 0015. 2400 marks the instant a day ends, so a shift ending at midnight may be written as 2400 rather than 0000 on the next date. The two refer to the same moment and differ only in which day they belong to.

Many organizations avoid the question by never writing 2400 and using 2359 as the last minute of the day instead. Copy whichever convention the rest of the sheet uses. What you should not do is write 0000 as the end of a shift without changing the date, because that reads as the shift finishing before it began.

Saying it out loud

• 0600 is spoken "zero six hundred", sometimes "oh six hundred".
• 0745 is "zero seven forty-five". Minutes are read as a plain number, not as "forty-five past".
• 1300 is "thirteen hundred". Hours ending in 00 always take "hundred".
• 1530 is "fifteen thirty".
• 2200 is "twenty-two hundred".
• 0000 is usually spoken as "zero hundred" or simply "midnight".

The word "hours" is often appended in formal speech, as in "fifteen thirty hours", though most workplaces drop it.

Where you run into it

Hospitals use 24-hour notation on medication charts and nursing notes, where a misread PM could double a dose. Aviation and shipping use it for flight plans and logs, often alongside UTC. The armed forces use it throughout, which is where the American nickname comes from, although most of the world simply calls it the 24-hour clock. It also turns up in dispatch logs, server timestamps and police reports, anywhere an entry might be read months later by someone who was not there.

Worked example: converting a shift schedule

A posted schedule lists three shifts in four-digit form. Converting them gives the times staff actually recognize, and the lengths are worth checking at the same time.

The day shift is the easy one: 1515 minus 0645 gives 8 hours and 30 minutes directly, because the 24-hour clock lets you subtract without worrying about the AM to PM boundary. That is the practical advantage of the notation.

The night shift needs splitting at midnight. From 2245 to 2400 is 1 hour 15 minutes, and from 0000 to 0715 is 7 hours 15 minutes, giving 8 hours 30 minutes in total. Subtract a 30 minute unpaid meal and each shift pays 8 hours, or 8.00 decimal hours. Three such shifts come to 24 paid hours. To total a week of four-digit entries without doing this by hand, use the military time card calculator, which accepts times typed as 0800 or 1700.

Frequently asked questions