From 2:30 PM to 1430, and back
Military time is the 24-hour clock written as four digits: two for the hour and two for the minutes, with no colon and no AM or PM. Enter a 12-hour time such as 2:30 PM and the page shows 1430. Enter 1430 and it shows 2:30 PM. Both directions work in the same box.
The page also shows how the time is read aloud. 1430 is said as "fourteen thirty". Times before 1000 start with a zero, so 0705 is "zero seven zero five". A time that ends in 00 usually takes the word hundred: 1200 is "twelve hundred" and 1800 is "eighteen hundred".
Midnight causes most of the confusion. 0000 is the start of a day and is said "zero hundred". 2400 is sometimes written for the end of a day in schedules, and "twenty-four hundred" is how it would be spoken, but it names the same instant as 0000 of the following date. Most systems use 0000 and 2359.
To convert by hand: for afternoon times add 12 to the hour, and for hours 1 to 9 in the morning add a leading zero. Twelve noon stays 12, and twelve midnight becomes 00.
Worked examples
Questions about this calculator
Is 0000 or 2400 the right way to write midnight?
Use 0000 for the start of a day. 2400 appears only to mean the very end of a day, and it is the same instant as 0000 on the next date.
Why is there no colon in military time?
Four plain digits are harder to misread over a radio or on a printed roster. The colon form, 14:30, is the same time in everyday 24-hour style.
Is 12:00 PM noon or midnight?
Noon. 12:00 PM is 1200. Midnight is 12:00 AM, which is 0000.