The US Military, including the US Army, all operate off of a 24-hour clock, most commonly known as Military Time. Military Time begins at 12:00am (midnight) (0000 called “Zero Hundred Hours”) and ends at 11:59 pm (2359 “Twenty-Three Fifty-Nine Hours”) the same day. So, 1:00 am is 0100 “Zero One Hundred” hours, 2:00 am is 0200 “Zero Two Hundred” hours, and so on up until 11:00 PM which is 2300 hours.
Military Time is simply continuing the clock after 12:59 pm. Instead of starting back at 1:00 pm, you’ll go to the next number higher than 12, which is 13. So 1:00 pm is 1300 “Thirteen Hundred” Hours in Military Time. Simple isn’t it?
Military Time List
Midnight (12:00 AM) — 0000 hrs
1:00 AM — 0100 hours
2:00 AM — 0200 hours
3:00 AM — 0300 hours
4:00 AM — 0400 hours
5:00 AM — 0500 hours
6:00 AM — 0600 hours
7:00 AM — 0700 hours
8:00 AM — 0800 hours
9:00 AM — 0900 hours
10:00 AM — 1000 hours
11:00 AM — 1100 hours
12:00 PM — 1200 hours
1:00 PM — 1300 hours
2:00 PM — 1400 hours
3:00 PM — 1500 hours
4:00 PM — 1600 hours
5:00 PM — 1700 hours
6:00 PM — 1800 hours
7:00 PM — 1900 hours
8:00 PM — 2000 hours
9:00 PM — 2100 hours
10:00 PM — 2200 hours
11:00 PM — 2300 hours
Simply add 12 to any PM number (for example, 3 pm) and you’ll get the military time equivalent, which in this case would be 3 pm + 12 = 15, so 1500 hours is the military time for 3 pm! So easy!
Military Time in Use
Army personnel use local time as a reference. In other words, “report to first formation at 0700,” would mean you have to be at your first formation at 7:00 AM, local time. “The First Sergeant wants to see you at 1600 hours,” means you need to be in the 1SG’s office at 4:00 PM, local time.
When using local military time, the Military observes Daylight Savings Time, if recognized by the state or country that the base is located in.
When it comes to operational matters (such as communications, training exercises, deployments, ship movements aircraft flights, etc.), the military must often coordinate with bases and personnel located in other time zones. To avoid confusion, in these matters, the military uses the time in Greenwich, England, which is commonly called Greenwich Mean Time (GMT). However, the U.S. Military refers to this time zone as Zulu Time, and they attach the “Zulu” (Z) suffix, to ensure the time zone referred to is clear.
For example, a military message or communication might state, “The ship will cross into the area of operations at 1300Z.” That means the ship would arrive in the AOO (Area Of Operations) when it is 1:00 PM in Greenwich, England.
Why does the military call this time “Zulu” Time? The world is divided into basically 24 time zones. For easy reference in communications, a letter of the alphabet has been assigned to each time zone. The time zone for Greenwich, England has been assigned the letter “Z.” The Military phonetic alphabet for the letter “Z” is “Zulu.”