1200 Military Time

1200 is 12:00 PM, noon. On a 24-hour clock with a colon it is 12:00; in military style the colon goes and the four digits stand alone. The hour is 12 hours after midnight and 12 hours before the next one.

Noon. The one hour where the two systems share digits: 12:00 PM and 1200 look alike, and 1230 is 12:30 PM, not 12:30 AM. Nothing is added or subtracted here.

To read it, look at the first two digits: the hour is exactly 12, which stays 12 and takes PM. This is the only PM hour where nothing is subtracted. The last two digits are minutes and never change, so 1225 is 12:25 PM and 1250 is 12:50 PM.

Military to 12-hour. Split the four digits into hours and minutes, the hour is exactly 12, which stays 12 and takes PM. This is the only PM hour where nothing is subtracted. So 1215 becomes 12:15 PM and 1245 becomes 12:45 PM.

12-hour to military. 12 PM keeps the 12. Noon is 1200 and 12:45 PM is 1245; only the AM hour after midnight changes to 00. Drop the colon and the AM or PM, and you have the four digits.

The mistakes worth knowing: “12:00 PM” is a mix of both systems and means nothing, because a 24-hour time already says which half of the day it is. And 1200 is not “12 AM”: 12 AM is midnight, 0000.

1200 is said “twelve hundred”. The “hundred” stands in for the two zeros; nobody says “thirteen zero zero”. Numbers from ten upward are said as ordinary numbers: “twelve hundred”, not “one two hundred”.

Minutes follow the same logic. 1205 is “twelve zero five” and 1240 is “twelve forty”. Single-digit minutes get a spoken zero, so the listener knows a digit is there.

About the word “hours”: in speech, “twelve hundred hours” is everywhere, and nobody will correct you. In writing, Army Regulation 25-50 says the word is not used with military time, so a memorandum reads “at 1200”, not “at 1200 hours”.

On its own, 1200 is local time wherever it is written. When the four digits carry a letter, the letter is the time zone. Z stands for Zulu, which is UTC, and J (Juliet) means the local time of the person speaking. The table converts 1200Z to the four US zones, in standard time and in daylight saving time.

Eastern Time is four hours behind UTC from March to November and five hours behind the rest of the year, which is why one Zulu time maps to two possible local times. The other three zones follow the same pattern an hour further west each.

Midnight has a second spelling, 2400, used when it marks the end of a day rather than the start. The full rules, with a converter, are on the military time chart page.