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Possible Duplicate:
Tool-tip timestamp shows a Z

Okay, I'm sure I'm just missing something obvious... but I've been thinking about it for a day now and I still haven't gotten it!

On the StackOverflow sites, why do some dates have "Z" after them? E.g., on my recent history: - why does it say "2010-01-11 08:10:54Z to 2010-01-11 23:59:59Z" instead of just "2010-01-11 08:10:54 to 2010-01-11 23:59:59"? Is it supposed to be an indicator of timezone, or of the fact that it's using 24-hour time rather than 12-hour?

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marked as duplicate by random, Ladybug Killer, alex, fretje, xmm0 Jan 11 '10 at 14:23

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Holy cow... I had never known before that UTC time could be referred to as "Zulu". Thanks, guys! :-) – Arkaaito Jan 11 '10 at 12:39

Z is for Zulu Time. Also known as Coordinated Universal Time, bizarrely abbreviated to UTC.

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Around these parts, we call it "Universal Coordinated Time", which doesn't match up with (the French) UTC abbreviation, but at least it's closer. :-) – Brian Knoblauch Jan 11 '10 at 14:34
Around these parts we call it JST : Jon Skeet Time – Jeff Atwood Jan 11 '10 at 14:54

Timezone; it just means the dates refer to UTC (roughly GMT), aka Zulu

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The Z in the time refers to the Zero timezone, and the NATO phonetic alphabet converts it to 'Zulu'.

And, of course, UTC+0hours is UTC.

The abbreviation UTC is a compromise between the French and English.

Francophones would prefer TUC (Temps Universel Coordonné), Anglophones would prefer CUT (Coordinated Universal Time),

so a compromise of UTC was chosen.

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Is that really the story? "I want TUC" "I want CUT" "We'll make it UTC so neither of us are happy!" This bodes well for international cooperation... – Tom Ritter Jan 11 '10 at 13:42
@Tom - yes: "In 1970 the Coordinated Universal Time system was devised by an international advisory group of technical experts within the International Telecommunication Union (ITU). The ITU felt it was best to designate a single abbreviation for use in all languages in order to minimize confusion. Since unanimous agreement could not be achieved on using either the English word order, CUT, or the French word order, TUC, the acronym UTC was chosen as a compromise." ( – Dominic Rodger Jan 11 '10 at 14:12
UTC looks better than any of the alternatives anyway. – Georg Schölly Jan 11 '10 at 14:47
Also TUC is overloaded with a few other things in the UK ("trades union congress", "tuc" biscuits) – Marc Gravell Jan 11 '10 at 15:05
@Tom Ritter: ever look up how the header size of the ATM protocol was chosen? :) – Ether Jan 11 '10 at 16:18

The Z comes from the Nautical Standard Time Zones and is used to represent the Zero Zone (today UTC). The other zones are names A-I and K-M (A-M skipping J)

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