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04:00 in 12-Hour Time
04:00 is 4:00 AM.
Written 0400 in military time and said “zero four hundred hours”. Going the other way, 4:00 AM is 04:00.
The 04:00 hour is the earliest hour on most bakery, market and freight timetables.
24-hour clock
04:00
12-hour clock
4:00 AM
Said aloud: “zero four hundred hours” on the 24-hour clock, “four o'clock at night” on the 12-hour one.
Why 04:00 converts the way it does
Every hour from 1 to 11 in the morning reads the SAME on both clocks — only the leading zero and the AM label differ. That is why converting a morning time feels like it did nothing: 04:xx and 4:xx AM are the same digits. The 24-hour form still pays for itself, because it cannot be mistaken for the afternoon.
The minutes are the same on both clocks — a whole hour stays a whole hour — and 04:00 is at night, which is the information the AM/PM label is carrying.
Need this time to actually do something? Set an alarm for 4:00 AM, or use the timer to count a length of time instead of waiting for a clock time.
Common questions
What is 04:00 in 12-hour time?
04:00 is 4:00 AM. The minutes are unchanged; the hour keeps its number and takes AM.
What is 4:00 AM in 24-hour time?
4:00 AM is 04:00, written 0400 in military time.
How do you say 0400 out loud?
In military time it is said "zero four hundred hours". On a 12-hour clock the same moment is "four o'clock at night".