I need a bet settled. A friend and I disagree on how ZULU TIME is used by the military. As i understand it, Zulu time is the same as Greenwich Meridian Time (Or UTC, Coordinated Universal Time). So if its 8:45PM EST here in NY, it's 00:45AM UTC( -5 hours). The question is, does a soldier stationed here in NY say it's 00:45 Z or 8:45PM?

[img]http://tycho.usno.navy.mil/gif/usnomc.gif[/img][img]http://tycho.usno.navy.mil/cgi-bin/utc.gif[/img][img]http://tycho.usno.navy.mil/gif/utc_tag.gif[/img]
Present UTC Time

Man, I just re-read that post, i cant wait for spring to get the hell out of this house.

-Hank

"does a soldier stationed here in NY say it's 00:45 Z or 8:45PM?"

Or to muddy the question further, would he say it's 2045...

I've only ever seen Zulu time used for written documents or, very occasionally, when it ws necessary to coordinate with people in different time zones.  And usually that coordination was in writing so...

not that i would know any better but the forts & post offices around here use 20:45

Also used in most op orders and and such. When we brief a multi ship mission we use zulu time.

Aviator

stop zulu time........................................................................................................................................................you can't touch this

Re-keying of Crypto, for commo nets and for things like IFF (Identification Friend or Foe)is generally done at midnight zulu - to keep everyone in sync. Also things like challenges and passwords, etc. are (usually) changed based on Zulu time. I say usually because I have seen more than one instance where a lack of clarity in an order caused some people to use local time and other Zulu time. At the tactical level, at least from a ground perspective, it is easier to just use local time - but important to make that clear or someone will read too much into it and do the conversion. On formal Operations order, time zone used will be stated in the heading, and all later date time group references will have the time immediatley followed by an "L" for local. Whenever you are dealing with larger scale ops though, zulu time is all I have seen used, as time zones are easily crossed.

Example, A few years back when I was playing curator of the Patriot Air Defense System at Al Jaber Air Base, Kuwait, I changed out the key to the IFF interrogator at 0300L, which was 2400Z. Our less secure SIF codes also changed same time. Incidentally, the Air Force liked to forget to change their own codes (as they are the ones who would publish them). I used to get a kick out of interrogating aircraft that I knew were friendlies, receiving a negative response and waiting a few minutes before trying again - and always getting the correct response. Gotta keep those damn Jet Jockeys honest.

BTW, I would say 8:45 PM in casual coversation, 2045 Local if clarity was required for a mission. I have always wondered about people who use 24 hr. time when dealing with "straights" (civilians) - just what are they trying to do - do they think it makes them look cool or something?

And yes, Zulu time = Greenwich Mean Time = Greenwich Meridian Time = Coordinated Universal Time. Any differences are anal bickering, like taking about when the millenium actually started.

Adam