2100 military time
2100 = 9:00 PM
2100 is 9 o’clock at night. With a colon it is 21:00.
Convert another time
How to read 2100
2100 is after noon, so subtract 12 from the hours: 21 − 12 = 9. Keep the minutes (00) and add PM: 9:00 PM. Do not subtract 10: 2100 is not 11:00 PM.
For hours 20 to 23, add 8 to the second digit: 21 gives 1 + 8 = 9, PM.
2100 falls in the night: 21 hours after midnight, 87.5% of the way through the day, with 3 hours left until the next midnight.
How to say it
Pilots and air traffic controllers say each digit: “two one zero zero”. Off the radio, people usually read 2100 as two numbers.
Counting hours to and from 2100
Start and end times on a timesheet come down to this subtraction. The decimal column is the form many payroll systems want; the minutes to decimal chart covers every minute.
| Start | Length | Decimal |
|---|---|---|
| 0600 | 15 h | 15.00 |
| 0700 | 14 h | 14.00 |
| 0800 | 13 h | 13.00 |
| 0900 | 12 h | 12.00 |
| Add | Military | 12-hour |
|---|---|---|
| 1 h | 2200 | 10:00 PM |
| 2 h | 2300 | 11:00 PM |
| 4 h | 0100 | 1:00 AM (next day) |
| 8 h | 0500 | 5:00 AM (next day) |
| 10 h | 0700 | 7:00 AM (next day) |
| 12 h | 0900 | 9:00 AM (next day) |
2100Z: the same moment in other time zones
Written 2100Z, the time is in UTC, and the local clock depends on the zone and the season.
| Zone | Standard time | Summer time |
|---|---|---|
| US Eastern (New York) | 4:00 PM UTC−5 | 5:00 PM UTC−4 |
| US Central (Chicago) | 3:00 PM UTC−6 | 4:00 PM UTC−5 |
| US Mountain (Denver) | 2:00 PM UTC−7 | 3:00 PM UTC−6 |
| US Pacific (Los Angeles) | 1:00 PM UTC−8 | 2:00 PM UTC−7 |
| Alaska (Anchorage) | 12:00 PM UTC−9 | 1:00 PM UTC−8 |
| Hawaii (Honolulu) | 11:00 AM UTC−10 | no change |
| UK (London) | 9:00 PM UTC+0 | 10:00 PM UTC+1 |
| Central Europe (Berlin) | 10:00 PM UTC+1 | 11:00 PM UTC+2 |
| India | 2:30 AM (next day) UTC+5:30 | no change |
| Japan and South Korea | 6:00 AM (next day) UTC+9 | no change |
| Australia East (Sydney) | 7:00 AM (next day) UTC+10 | 8:00 AM (next day) UTC+11 |
For a particular date and city, use the time zone converter, which applies the exact daylight saving dates.
Nearby military times
The full chart is on the military time page.