Military time is the 24-hour clock written without a colon: hours run from 00 to 23, so for any p.m. time from 1:00 to 11:59, add 12 to the hour (5:30 p.m. = 1730). For a.m. times, keep the hour and add a leading zero (9:15 a.m. = 0915), except that 12:xx a.m. becomes 00xx. To go back, subtract 12 from hours 13–23 and add "p.m."
NIST notes that "12 a.m." and "12 p.m." are ambiguous and recommends naming noon and midnight, or using the 24-hour clock with 0000 for midnight at the start of a day and 2400 for midnight at its end. Type any time in either format below.
How to use the military time converter (24-hour clock)
- Type a time in 12-hour form (5:30 pm, 9 am) or 24-hour form (1730, 17:30).
- Read the military time and the standard time.
- Use the chart below for quick lookups.
Formula
Worked example
Convert 5:30 p.m. and 2145.
- 5:30 p.m. → 5 + 12 = 17 → 1730 ("seventeen thirty hours").
- 2145 → 21 − 12 = 9 → 9:45 p.m.
- 12:20 a.m. → 0020; 12:20 p.m. → 1220.
Military time chart
| Standard | Military | Standard | Military |
|---|---|---|---|
| Midnight | 0000 | Noon | 1200 |
| 1 a.m. | 0100 | 1 p.m. | 1300 |
| 2 a.m. | 0200 | 2 p.m. | 1400 |
| 3 a.m. | 0300 | 3 p.m. | 1500 |
| 4 a.m. | 0400 | 4 p.m. | 1600 |
| 5 a.m. | 0500 | 5 p.m. | 1700 |
| 6 a.m. | 0600 | 6 p.m. | 1800 |
| 7 a.m. | 0700 | 7 p.m. | 1900 |
| 8 a.m. | 0800 | 8 p.m. | 2000 |
| 9 a.m. | 0900 | 9 p.m. | 2100 |
| 10 a.m. | 1000 | 10 p.m. | 2200 |
| 11 a.m. | 1100 | 11 p.m. | 2300 |
Military time is commonly spoken as two pairs of digits followed by "hours" (1700 is "seventeen hundred hours"; 0830 is "zero eight thirty"). Conventions vary by service and organization. To find the hours between two times, use the time duration calculator (hours between two times).
Converting step by step
12-hour to 24-hour:
- If the time is a.m. and the hour is 1–11, keep the hour and pad it to two digits (7:05 a.m. → 0705).
- If the time is 12:xx a.m. (the hour after midnight), change the hour to 00 (12:40 a.m. → 0040).
- If the time is 12:xx p.m. (the hour after noon), keep 12 (12:40 p.m. → 1240).
- For any other p.m. time, add 12 to the hour (7:05 p.m. → 1905).
24-hour to 12-hour: if the hour is 00, write 12 and a.m.; if it is 01–11, drop the leading zero and write a.m.; if it is 12, write p.m.; if it is 13–23, subtract 12 and write p.m.
Where the 24-hour clock is used
Outside the United States, the 24-hour clock is the everyday way of writing time in many countries, on train and flight timetables, and in hospitals, emergency services and computing, because it removes the a.m./p.m. ambiguity. A schedule that says a shift runs "2200–0600" is unambiguous; "10–6" is not.
In written 24-hour time, a colon (17:30) is common in civilian use, while military style usually drops it (1730). Both mean the same thing. When you need the length of a shift written this way, enter the start and end in the time duration calculator (hours between two times), which handles shifts that cross midnight.
Caveats and assumptions
- Converts the clock format only; time zones are not converted.
- Spoken forms vary by organization.
Frequently asked questions
What is 1700 in military time?
5:00 p.m.
How do I convert p.m. times to military time?
Add 12 to the hour (except 12 p.m., which stays 1200). 3:45 p.m. = 1545.
Is midnight 0000 or 2400?
Both are used: 0000 is midnight at the start of a day and 2400 is midnight at the end of a day, as NIST describes.
Is 12 p.m. noon or midnight?
Conventionally 12 p.m. means noon, but NIST calls 12 a.m./12 p.m. ambiguous and suggests writing "noon" or "midnight" (or 1200 / 0000).
What is 2000 in regular time?
8:00 p.m. (20 − 12 = 8).
What time is 0000?
Midnight at the start of the day, shown as 12:00 a.m. on a 12-hour clock.
Sources
- NIST — Times of Day FAQs — 12 a.m./p.m. ambiguity; 0000 and 2400 for midnight
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