1700 Military Time

1700 is 5:00 PM, five o’clock in the evening. On a 24-hour clock with a colon it is 17:00; in military style the colon goes and the four digits stand alone. The hour is 17 hours after midnight and 7 hours before the next one.

Five in the afternoon, the end of the standard working day and, by search volume, the most looked-up military time of all.

To read it, look at the first two digits: the hour is above 12, so subtract 12 and add PM: 17 − 12 = 5. The last two digits are minutes and never change, so 1725 is 5:25 PM and 1750 is 5:50 PM.

Military to 12-hour. Split the four digits into hours and minutes, the hour is above 12, so subtract 12 and add PM: 17 − 12 = 5. So 1715 becomes 5:15 PM and 1745 becomes 5:45 PM.

12-hour to military. 5 PM is a PM hour, so add 12: 5 + 12 = 17. 5:05 PM is 1705. Drop the colon and the AM or PM, and you have the four digits.

The mistakes worth knowing: “17:00 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 1700 is not 17:00 AM; there is no 17 o’clock in the morning.

1700 is said “seventeen hundred”. The “hundred” stands in for the two zeros; nobody says “thirteen zero zero”. Numbers from ten upward are said as ordinary numbers: “seventeen hundred”, not “one seven hundred”.

Minutes follow the same logic. 1705 is “seventeen zero five” and 1740 is “seventeen forty”. Single-digit minutes get a spoken zero, so the listener knows a digit is there.

About the word “hours”: in speech, “seventeen 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 1700”, not “at 1700 hours”.

On its own, 1700 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 1700Z 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.