00:00 in 12-Hour Time
00:00 is 12:00 AM.
Written 0000 in military time and said “zero zero hundred hours”. Going the other way, 12:00 AM is 00:00.
The 00:00 hour is the start of the day on every 24-hour clock, and the one that catches people out: it is 12 AM, not 12 PM. Timetables and hospital charts write the date change here.
24-hour clock
00:00
12-hour clock
12:00 AM
Said aloud: “zero zero hundred hours” on the 24-hour clock, “twelve midnight” on the 12-hour one.
Why 00:00 converts the way it does
Midnight is the first of the two times people get wrong. On the 24-hour clock the day starts at 00:00; on the 12-hour clock the same moment is 12:00 AM — twelve, and AM. It is never 12 PM, and 24:00 is the same instant written as the END of the previous day, which is why a timetable will show a service departing at 00:10 on Tuesday and never at 24:10 on Monday.
The minutes are the same on both clocks — a whole hour stays a whole hour — and 00:00 is at night, which is the information the AM/PM label is carrying.
Need this time to actually do something? Set an alarm for 12:00 AM, or use the timer to count a length of time instead of waiting for a clock time.
Common questions
What is 00:00 in 12-hour time?
00:00 is 12:00 AM. The minutes are unchanged; the hour 00 becomes 12 and takes AM, because 00:00 is midnight.
What is 12:00 AM in 24-hour time?
12:00 AM is 00:00, written 0000 in military time.
How do you say 0000 out loud?
In military time it is said "zero zero hundred hours". On a 12-hour clock the same moment is "twelve midnight".