How to use this calculator
The military time converter changes a time between the 12-hour clock, with AM and PM, and the 24-hour clock used for military time. Enter a 12-hour time to get its four-digit military form, or enter a military time to get the 12-hour form. Each result also shows how the time is usually spoken, such as “fifteen thirty hours” for 1530 or “zero six hundred hours” for 0600.
A chart below lists all 24 hours of the day with both forms side by side, from 0000 (12 AM) to 2300 (11 PM). Use it to read a schedule, a shift roster or a log written in 24-hour time. The converter only changes notation; it does not convert between time zones. For a time in another location, use the time zone converter.
Formula and calculation method
12-hour to 24-hour: 12 AM → 00; 1–11 AM unchanged; 12 PM → 12; 1–11 PM → hour + 12. Minutes are unchanged; write as four digits.
From 12-hour to military time
For an AM time from 1 to 11, keep the hour and add a leading zero if needed: 6:30 AM becomes 0630. For 12 AM, which is midnight, the hour becomes 00, so 12:15 AM becomes 0015. For 12 PM, which is noon, the hour stays 12, so 12:45 PM becomes 1245. For any other PM hour, add 12: 3:30 PM becomes 1530 and 11:05 PM becomes 2305. The minutes never change. Military time is written as four digits with no colon and no AM or PM.
From military time to 12-hour
Read the first two digits as the hour. 00 is 12 AM. 01 to 11 are AM with the same hour. 12 is 12 PM. For 13 to 23, subtract 12 and use PM: 1945 is 7:45 PM and 2200 is 10:00 PM. The last two digits are the minutes. When speaking, a time on the hour is said as “hundred hours”, so 1400 is “fourteen hundred hours”, and a leading zero is usually pronounced as “zero”.
Worked examples
An afternoon time
3:30 PM is a PM hour other than 12, so add 12 to the hour: 3 + 12 = 15. The result is 1530, spoken as “fifteen thirty hours”. Converting back, 15 − 12 = 3, which gives 3:30 PM. The same rule turns 7:45 PM into 1945, “nineteen forty-five hours”, and 11:59 PM into 2359, the last minute of the day.
An early-morning time
6:00 AM keeps its hour, and a leading zero makes four digits: 0600, spoken as “zero six hundred hours”. Half an hour later, 6:30 AM is 0630. Times between midnight and 1 AM start with 00: 12:30 AM becomes 0030. Writing 1230 for that time would be wrong, because 1230 is half past noon.
Noon and midnight
12 PM is noon and stays 1200, “twelve hundred hours”; 12 PM plus 12 would give 24, which is not used for noon. 12 AM is midnight at the start of a day and becomes 0000. Some schedules write 2400 to mark midnight at the end of a day, so 2400 on Monday and 0000 on Tuesday are the same moment. A shift written as 1600 to 2400 ends at midnight that night.
Edge cases and practical checks
Time zone letters
Military messages often add a letter after the time to show its time zone. Z, spoken “Zulu”, means UTC, so 1530Z is 15:30 UTC. Other letters stand for other offsets from UTC; for example, R (Romeo) is UTC−5, which is Eastern Standard Time in the United States, and the letter J (Juliet) means the observer’s local time. The converter changes notation only and does not apply these offsets. To convert 1530Z to a local time, use the time zone converter.
Seconds and other formats
Military time is normally written in hours and minutes only. When seconds are needed, they are added as two more digits or after a colon in civilian 24-hour notation, as in 15:30:45. Outside the military, the 24-hour clock is usually written with a colon, as in 15:30, and many countries use it for everyday times. The digits are the same; only the separator and the spoken form differ.
Frequently asked questions
What is 1800 in regular time?
1800 is 6:00 PM. The hour 18 is greater than 12, so subtract 12 to get 6, and use PM. It is spoken as “eighteen hundred hours”.
Is midnight 0000 or 2400?
Midnight at the start of a day is 0000, and that is the usual form. Some schedules and contracts use 2400 to mark the end of a day, which is the same moment as 0000 on the next day. Times after midnight continue from 0001, never 2401.
Is 12 PM noon or midnight?
12 PM is noon, written 1200 in military time. 12 AM is midnight, written 0000. The rule of adding 12 for PM times applies only to the hours from 1 PM to 11 PM.
Why is there no colon in military time?
Military time is written as four digits so that it is short and cannot be confused with other numbers in a message. The leading zero is kept, so 7:05 AM is 0705 rather than 705. Civilian 24-hour time usually keeps the colon, as in 07:05.
How do you say 0030 aloud?
It is commonly said as “zero zero thirty hours”. In general, each leading zero is spoken as “zero”, the hour and minutes are read as numbers, and “hours” may be added at the end. Practice varies between services and countries, so follow the convention your organisation uses.
What does the Z after a time mean?
Z stands for Zulu time, which is UTC, the time at zero degrees longitude without daylight saving time. A time such as 0900Z is the same moment everywhere, which is why it is used in aviation, weather reports and military communication.