0100 at a glance
- 12-hour time
- 1:00 AM
- 24-hour clock
- 01:00
- Say it
- zero one hundred hours
- Part of day
- Night (after midnight)
- Minutes after midnight
- 60
- Minutes until midnight
- 1,380
- Decimal hours
- 1.00
- Share of the day gone
- 4.17%
How to convert 0100 to standard time
- The hour digits are 01. Hours 01 to 11 are the same on both clocks — just drop the leading zero: 1.
- Put a colon before the minutes and add AM: 1:00 AM.
How to say 0100
| Style | How it sounds |
|---|---|
| Military (spoken) | “zero one hundred hours” |
| Short form | “zero one hundred” |
| Radio, digit by digit | “zero one zero zero” |
| Civilian | “one o’clock in the morning” |
| Written 24-hour | 01:00 or 0100 |
On the hour, the minutes are spoken as “hundred”: 0100 is “zero one hundred hours.” The leading zero is spoken too.
0100 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 0100Z, this is the local time across the United States:
| Time zone | Standard time | Daylight time |
|---|---|---|
| Eastern (EST / EDT) | 8:00 PM (previous day) — R | 9:00 PM (previous day) — Q |
| Central (CST / CDT) | 7:00 PM (previous day) — S | 8:00 PM (previous day) — R |
| Mountain (MST / MDT) | 6:00 PM (previous day) — T | 7:00 PM (previous day) — S |
| Pacific (PST / PDT) | 5:00 PM (previous day) — U | 6:00 PM (previous day) — T |
| Alaska (AKST / AKDT) | 4:00 PM (previous day) — V | 5:00 PM (previous day) — U |
| Hawaii (HST) | 3:00 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 0100Z is 2000R. 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 0100 is your local time
- 0100 Eastern is 0600Z in winter (EST) and 0500Z in summer (EDT).
- 0100 Central is 0700Z in winter (CST) and 0600Z in summer (CDT).
- 0100 Mountain is 0800Z in winter (MST) and 0700Z in summer (MDT).
- 0100 Pacific is 0900Z in winter (PST) and 0800Z in summer (PDT).
Times around 0100
| Change | Military | Standard |
|---|---|---|
| −60 min | 0000 | 12:00 AM |
| −45 min | 0015 | 12:15 AM |
| −30 min | 0030 | 12:30 AM |
| −15 min | 0045 | 12:45 AM |
| This time | 0100 | 1:00 AM |
| +15 min | 0115 | 1:15 AM |
| +30 min | 0130 | 1:30 AM |
| +45 min | 0145 | 1:45 AM |
| +60 min | 0200 | 2:00 AM |
Shifts that start at 0100
- An 8-hour shift starting at 0100 ends at 0900 (9:00 AM).
- A 10-hour shift starting at 0100 ends at 1100 (11:00 AM).
- A 12-hour shift starting at 0100 ends at 1300 (1:00 PM).
- To total the hours on a real time card with breaks, use the time card calculator.
0100 in everyday use
- 0100 falls in the overnight hours — the time of night shifts, red-eye flights and early deliveries. Writing it as 0100 instead of 1:00 AM removes any doubt about whether the morning or the evening is meant.
- On the day US clocks fall back in November, the hour from 0100 to 0159 happens twice, so 0100 occurs once in daylight time and again in standard time. Logs and timesheets kept in local time need a note for that night.
Frequently asked questions
What is 0100 in regular time?
0100 is 1:00 AM in regular 12-hour time.
Is 0100 AM or PM?
0100 is AM. Military times from 0000 to 1159 are AM and times from 1200 to 2359 are PM.
How do you say 0100 in military time?
Say “zero one hundred hours.” In radio procedure each digit is spoken separately, so 0100 can also be read digit by digit.
What is 0100 Zulu in Eastern time?
0100Z is 8:00 PM (previous day) Eastern Standard Time (UTC−5) and 9:00 PM (previous day) Eastern Daylight Time (UTC−4).