0400 at a glance
- 12-hour time
- 4:00 AM
- 24-hour clock
- 04:00
- Say it
- zero four hundred hours
- Part of day
- Night (after midnight)
- Minutes after midnight
- 240
- Minutes until midnight
- 1,200
- Decimal hours
- 4.00
- Share of the day gone
- 16.67%
How to convert 0400 to standard time
- The hour digits are 04. Hours 01 to 11 are the same on both clocks — just drop the leading zero: 4.
- Put a colon before the minutes and add AM: 4:00 AM.
How to say 0400
| Style | How it sounds |
|---|---|
| Military (spoken) | “zero four hundred hours” |
| Short form | “zero four hundred” |
| Radio, digit by digit | “zero four zero zero” |
| Civilian | “four o’clock in the morning” |
| Written 24-hour | 04:00 or 0400 |
On the hour, the minutes are spoken as “hundred”: 0400 is “zero four hundred hours.” The leading zero is spoken too.
0400 Zulu (UTC) in US time zones
Military and aviation schedules give times in Zulu — Coordinated Universal Time — so that everyone works from one clock. When a message says 0400Z, this is the local time across the United States:
| Time zone | Standard time | Daylight time |
|---|---|---|
| Eastern (EST / EDT) | 11:00 PM (previous day) — R | 12:00 AM — Q |
| Central (CST / CDT) | 10:00 PM (previous day) — S | 11:00 PM (previous day) — R |
| Mountain (MST / MDT) | 9:00 PM (previous day) — T | 10:00 PM (previous day) — S |
| Pacific (PST / PDT) | 8:00 PM (previous day) — U | 9:00 PM (previous day) — T |
| Alaska (AKST / AKDT) | 7:00 PM (previous day) — V | 8:00 PM (previous day) — U |
| Hawaii (HST) | 6:00 PM (previous day) — W | No daylight time |
The letter after each time is that zone’s military time-zone letter: Eastern standard time is R (Romeo, UTC−5), so 0400Z is 2300R. Daylight time runs from the second Sunday in March to the first Sunday in November; Hawaii and most of Arizona stay on standard time all year.
If 0400 is your local time
- 0400 Eastern is 0900Z in winter (EST) and 0800Z in summer (EDT).
- 0400 Central is 1000Z in winter (CST) and 0900Z in summer (CDT).
- 0400 Mountain is 1100Z in winter (MST) and 1000Z in summer (MDT).
- 0400 Pacific is 1200Z in winter (PST) and 1100Z in summer (PDT).
Times around 0400
| Change | Military | Standard |
|---|---|---|
| −60 min | 0300 | 3:00 AM |
| −45 min | 0315 | 3:15 AM |
| −30 min | 0330 | 3:30 AM |
| −15 min | 0345 | 3:45 AM |
| This time | 0400 | 4:00 AM |
| +15 min | 0415 | 4:15 AM |
| +30 min | 0430 | 4:30 AM |
| +45 min | 0445 | 4:45 AM |
| +60 min | 0500 | 5:00 AM |
Shifts that start at 0400
- An 8-hour shift starting at 0400 ends at 1200 (12:00 PM).
- A 10-hour shift starting at 0400 ends at 1400 (2:00 PM).
- A 12-hour shift starting at 0400 ends at 1600 (4:00 PM).
- To total the hours on a real time card with breaks, use the time card calculator.
0400 in everyday use
- 0400 falls in the overnight hours — the time of night shifts, red-eye flights and early deliveries. Writing it as 0400 instead of 4:00 AM removes any doubt about whether the morning or the evening is meant.
- Military slang for an uncomfortably early start is “zero-dark-thirty” — any time well before dawn, like 0400.
Frequently asked questions
What is 0400 in regular time?
0400 is 4:00 AM in regular 12-hour time.
Is 0400 AM or PM?
0400 is AM. Military times from 0000 to 1159 are AM and times from 1200 to 2359 are PM.
How do you say 0400 in military time?
Say “zero four hundred hours.” In radio procedure each digit is spoken separately, so 0400 can also be read digit by digit.
What is 0400 Zulu in Eastern time?
0400Z is 11:00 PM (previous day) Eastern Standard Time (UTC−5) and 12:00 AM Eastern Daylight Time (UTC−4).