What is 2000 in military time?
2000 is 8:00 PM on the 12-hour clock, and 20:00 on the civilian 24-hour clock. It is spoken aloud as “twenty zero hundred hours” — never “8 o'clock”, and never with a colon in the written form.
The hour is over 12, so subtract 12: 20 − 12 = 8, and the time is PM.
Written down it is four digits with no separator and no AM or PM: 2000. The first two digits are the hour, the last two are the minutes, and the minutes are ordinary minutes — 2045 would be 8:45 PM.
Where 2000 sits in the day
2000 is 20 hours into the day and 4 hours from the next midnight. In the watch system it falls in the first watch, the night block that runs up to midnight. Lights out, night flying and the last departures of the day sit here, and the hour numbers are as far from their 12-hour equivalents as they ever get.
The hours either side
Three hours in each direction, since the value you are checking is usually next to the one you actually need.
Everything else on the 24-hour clock
The full chart lists every hour and half hour from 0000 to 2330 and prints on one page — that link jumps straight to the 2000 row. For a value that is not on a half hour, the military time converter takes anything you type in either direction, including 8:00 PM and 2000.
If what actually tripped you up was midnight versus noon rather than this hour, the 12 AM vs 12 PM explainer covers why the 12-hour clock cannot settle that question on its own.