Military time is a 24-hour clock system that runs from 0000 (midnight) to 2359 (11:59 PM). Unlike the standard 12-hour clock, military time eliminates AM and PM, making it unambiguous for scheduling, aviation, medicine, and the military.

For AM hours: simply remove the colon and add a leading zero if needed (e.g., 9:30 AM = 0930). For PM hours: add 12 to the hour (e.g., 2:30 PM = 1430). Midnight is 0000, and noon is 1200.

0000 (spoken as "zero hundred hours") is midnight — the start of a new day. It is also sometimes written as 2400, which represents the end of the previous day. Most military and aviation contexts use 0000 for midnight.

Military time is used by the armed forces, hospitals and medical professionals, emergency services (police, fire, paramedics), airlines and aviation, and most countries outside the United States use the 24-hour format as their standard.

Military time is spoken differently than standard time. 0900 is "zero nine hundred hours," 1300 is "thirteen hundred hours," and 1430 is "fourteen thirty." The word "hours" is typically added at the end.

1800 military time is 6:00 PM in standard time. To convert, subtract 12 from any military time hour above 1200: 18 - 12 = 6, so 1800 = 6:00 PM.