Military Time Explained: Conversion, Chart and Pronunciation

How the 24-hour clock works, how to convert both ways in your head, how to say it, and the midnight edge cases.

Actualizado 2026-10-20

Esta guía está disponible en inglés por ahora; la traducción al español llegará pronto.

Military time is the 24-hour clock written as four digits with no colon: 0900 is 9:00 AM, 1730 is 5:30 PM. Hospitals, airlines, the military and many time clocks use it because there is no AM/PM to get wrong.

Converting standard to military

AM hours (1 to 11): pad to two digits. 7:05 AM → 0705. 12 PM (noon): 1200. PM hours (1 to 11): add 12. 5:30 PM → 1730. 12 AM (midnight): 0000.

Converting military to standard

0000 to 0059: 12 AM. 0030 → 12:30 AM. 0100 to 1159: same hour, AM. 0930 → 9:30 AM. 1200 to 1259: 12 PM. 1300 to 2359: subtract 12, PM. 2115 → 9:15 PM.

Chart

The full chart page generates every hour, half hour or quarter hour and can be printed.

Pronunciation

Say the hour as two digits, then the minutes, then “hours”. 0900 is “zero nine hundred hours”. 1730 is “seventeen thirty hours”. 0005 is “zero zero zero five hours”. Civilians using the 24-hour clock drop the “hours”.

Midnight: 0000 or 2400

0000 is the start of a day; 2400 is the end of the previous one. A shift from 1600 to 2400 ends at midnight on the same date; one from 0000 to 0800 starts at midnight. Timesheets usually record 2400 as the out time and 0000 as the in time. Our time parser accepts both.

In spreadsheets

Excel and Google Sheets need a colon: type 17:30, not 1730. A bare 1730 is the number one thousand seven hundred thirty. To convert a typed number: =TIME(INT(A1/100),MOD(A1,100),0).

Military time versus Zulu time

Military time is just the 24-hour clock in local time. Zulu time is the 24-hour clock in UTC, written with a Z: 1730Z. See the Zulu time guide.

Converting durations in military time

Subtract as you would any 24-hour times. 0745 to 1615: 16:15 − 7:45 = 8:30. Across midnight add 24: 2200 to 0600 is 6 + 24 − 22 = 8 hours. Minutes are still base 60, so 1615 − 0745 is not 870 by ordinary subtraction; convert to minutes since midnight (975 − 465 = 510) and back (8:30).

Where you will see it

Hospitals chart medication times in 24-hour form to avoid a 10x dosing-interval error between 8:00 AM and 8:00 PM. Airlines print departure times as 0635. Military orders use it with a zone letter. Many time clocks and payroll exports print 24-hour times because they sort correctly as text. Europe and most of the world use the 24-hour clock in everyday writing, usually with a colon (17:30) and without the leading zero in speech.

Common mistakes

• Writing 12:30 PM as 0030. Half past noon is 1230; 0030 is half past midnight.
• Reading 1500 as 5:00 PM. 1500 is 3:00 PM (15 − 12).
• Adding 12 to a 24-hour time that is already past noon.
• Typing 1730 into a spreadsheet and getting the number 1,730.

Quarter-hour table

Frequently asked

What time is 1800? 6:00 PM.

What is 0000 in standard time? 12:00 AM, midnight, the start of the day.

Is 2400 valid? As the end of a day, yes; a shift ending at 2400 ends at midnight. Clocks display 0000 a moment later.

How do you say 0030? “Zero zero thirty hours.” Some units say “zero zero thirty” without “hours”.

Does military time use seconds? For most purposes no, but logs that need them write 173045 or 17:30:45.