What time is 21:00?

21:00 is 9:00 PM on a 12-hour clock and "21:00 Hours" in Military Time. We use this system throughout the world (not just the military) and leverages a 24-hour time clock rather than the 12-hour AM/PM system known to most English-speaking countries. Below are ways to convert 21:00 through a time chart, automated calculator, and ways to convert by hand.

21:00 conversion cheat sheet & time chart

How to convert 21:00 from 24-Hour Time to 12-Hour Standard Time

It is easy to convert from 24-hour time to 12-hour time once you know a few tricks. The primary difference between the two is that the hours in a 24-hour clock go all the way up to 23 (from 0 to 23). In a 12-hour clock, the hour resets to 1 after noon (midday). Follow the steps below to convert 21:00 to 12-hour time.

1. First, determine whether or not 21 is greater than 12 (recall that this is one of the distinctions of the 12-hour clock, there are no hours "greater" than 12 on it)
2. The hour 21 is higher than twelve, so we need to subtract 12 from 21 to get our "PM" hour: 21 - 12 = 9
3. Now add "PM" to the end of the time: 9:00 PM

DID YOU KNOW?

24-hour time is used in aviation, military, meteorology, logistics, and other fields. The 12-hour clock is only used in 18 countries globally, including the United States and Canada. 24-hour time and military time are very similar! See our military time converter for more information.

21 Hour Conversion Chart