0400 hours = 4:00 AM
0400 hours is 4:00 AM in standard 12-hour time. On a 24-hour clock it is 04:00. Spoken military time is “zero four hundred hours”.
How to convert 0400
0400 is a morning time (hour 4 on the 24-hour clock). Drop any leading zero and add AM: 4:00 AM. Hours 0000–1159 are all AM.