[Bigg Red]

Did not mean to disparage the military.

What is the origin of “Zulu Time”?

Military doesn’t use UT, though, right?

[LonePalm]

I can help you with Military time zones.

Zulu = GMT
Going East from Zulu counts up Alpha, Bravo, Charlie, Delta, ....

Going West from Zulu counts up November, Oscar, Papa, Quebec, ....
Eastern Standard Time is Romeo.

Military Message Date Time Groups are ALWAYS in Zulu and take the form "YYYYMMDDHHmmZ".

WWG1WGA

Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)

[xone]

What is the origin of “Zulu Time”?

'I should point out that Zulu is the NATO phonetic alphabet name for the Z used for the military timezone where the local time is UTC. The U.S. military uses other letters to refer to other timezones.'

Military doesn’t use UT, though, right?

" Short version: the "fundamental" time standards are UT1 and TAI. UT1 is measured by the position of the sun from the Royal Observatory in Greenwich; TAI is measured by atomic clocks." ; TAI gets out of sync with everyday notions of time as measured by the sun and stars. The solution is UTC, which is just TAI plus or minus an integer number of leap seconds, to keep it close to UT1. Greenwich Mean Time technically means UT1, but is commonly used to refer to UTC nowadays.

Time

So, GMT/UTC/Zulu are at times (no pun intended) equivalent. Zulu and UTC are not corrected to DST where GMT is. Further while GMT refers to time established by the position of the sun from the Royal Observatory in Greenwich it is usually called UTC nowadays.

Confused? Now you know why aviation and the military use Zulu, to coordinate or schedule over many time zones. It gets worse going from FAA control to ICAO. Takes a bit to re-familiarize yourself with the terminology and procedures.

[Billyv]

UT time is used by the ICAO and FAA in their automated time broadcasts on the HF nets. Big clock in the sky to synchronize the watches by.