List of military time zones

This is a list of time zones as used by the U.S. military and others. The names are based on the NATO phonetic alphabet (with two spelling changes: Alpha for "Alfa", Juliet for "Juliett").

Going east from the prime meridian at Greenwich, letters Alpha through Mike (skipping "J", see below) are used for the 12 time zones with mainly positive UTC offsets until reaching the International Date Line. Going west from Greenwich, letters November through Yankee are used for zones with negative time offsets.

The system originates with Nathaniel Bowditch's 1802 American Practical Navigator where time zones were labelled with letters: the letter "J" was skipped to avoid confusion with "I" (as was the custom of the time) and because some alphabets don't have one (such as Cyrillic).

The letter J ("Juliet"), originally skipped, is now used to indicate the observer's local time.

The letter Z ("Zulu") indicates Greenwich Mean Time (GMT) or Coordinated Universal Time (see UTC±00:00).

They are used in conjunction with military time: for instance, 6:00 a.m. in zone UTC-5 is written "0600R" and spoken "zero six hundred Romeo".

The use of Military TimeZones for the Internet is described in RFC 822, which can be found on IETF.org.