Military time converter

Type a time such as 2:30 PM, 9am or noon. The military time appears as you type, with the 24-hour form, how to say it and the digit-by-digit radio reading.

Swap the boxes to go the other way. Type 1430, 14:30 or 1430Z and you get the 12-hour time. Put one time on each line to convert a whole list.

For a morning time, keep the hour and add a leading zero if it's a single digit, so 9:15 AM is 0915. For an afternoon or evening time, add 12 to the hour, so 2:30 PM is 1430. Then drop the colon. Minutes never change.

The two twelves are the catch. 12 PM is noon and stays 1200, but 12 AM is midnight and becomes 0000. Going back, subtract 12 from any hour above 12 and add PM.

In US and allied military use, leading zeros are always spoken. 5:43 AM is "zero five forty-three", or "zero five four three" on the radio. On the hour, the word is hundred, never thousand, so 2000 is "twenty hundred".

A letter on the end names the time zone, read with the NATO alphabet. Z is UTC, which is why it's called Zulu time. J, Juliett, means local time, so 1200J is noon wherever you are.

The day starts at 0000. 2400 can mark the midnight at the end of a day, the same moment as 0000 the next day, so a shift might run from 1600 to 2400.

Because the two are easy to mix up, some style guides and military rules suggest writing 2359 or 0001 for anything near midnight instead, so that every time clearly belongs to one date and nobody turns up a day late.