Talk:Time zone

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[edit] Missing time zone

The article is excellent, but appears to be missing NBT - New Baby Time. In this zone, days and nights merge and the rotation of the earth is replaced by a much faster cycle - the state of said baby's stomach. —Preceding unsigned comment added by Stephen B Streater (talk • contribs) 11:51, 25 February 2006

[edit] Majorly Plaigarised?

FWIW, a great bulk of the text for this article appears to have been lifted directly from http://www.enquirerworld.com/zones.html. Perhaps it was done with permission (or by the same author) -- perhaps not. (I notice the site enquirerworld.com isn't listed in the external links.) Thought some Wiki-Master might want to check this out. (Unsigned edit by User:4.235.51.214)

{{copyvio}} placed. Pavel Vozenilek 04:58, 15 March 2006 (UTC)
Enquirerworld.com is clearly a Wikipedia mirror site, although they are violating the terms of the GFDL by not crediting Wikipedia. All of their articles are copied from Wikipedia. Someone should add them to Wikipedia:Mirrors and forks. Rhobite 05:01, 15 March 2006 (UTC)

[edit] minor edit

some people have strange ideas of what constitutes a minor edit :-) [1] Thanks to Stephen.frede for reverting. best regards Tobias Conradi (Talk) 02:00, 18 March 2006 (UTC)

[edit] Suggestion

I want to suggest that the list of Time Zone from UTC-12 to UTC+14 to restore in the Time Zone article because I want to inform the new user which they are the first open in the Time Zone article. Joseph Solis (talk) 09:15, 18 March 2006 (UTC)

Oppose. Having the whole list in the main article detracts from the quality of the article. It is quite easy for anyone looking to see the list in the separate article for that purpose. I'm not sure what you mean by specifically referencing "the new user". Articles should be written to be the best they possibly can be, regardless of who is reading them. Stephen.frede 09:52, 18 March 2006 (UTC)
Oppose as well. The list should have its own article. —Nightstallion (?) 11:34, 18 March 2006 (UTC)
Oppose. One can have a "list of Xs" in an article "X". But if the article itself and the list become very large it is IMO better to have them separated. AFAIK there is even a policy regarding article length, that suggests splitting. I even would like to remove the see also "list of time zones" from the top. I never saw anything like this in WP. The see also section is very good for this purpose, maybe the list can be bolded there. Tobias Conradi (Talk) 00:56, 19 March 2006 (UTC)

I am now agree to Stephen.frede, Nightstallion, and Tobias Conradi.--Joseph Solis--02:00 UTC, April 4, 2006

-) Tobias Conradi (Talk) 17:18, 7 April 2006 (UTC)

[edit] One really confusing point

Do the various time zones generally correspond to UTC year round? Or do they go one-off during daylight saving?

In other words, is New York "in" UTC-5 all the time? Or would it be more correct to say that New York observes UTC-5 during regular time and UTC-4 during daylight saving?

I want to know soon, because the answer to this will determine a slew of edits to a couple dozen articles. --Uncle Ed 00:07, 23 March 2006 (UTC)

I would say it observers -5 and -4. Traditionally the -5 is called standard and the other is called DST.
BTW I would like more mentionings of UTC+-XY linked to the UTC+-XY articles. E.g. Country templates, or US state templates mention UTC offset. but the offset is not linked. only "UTC" is. Tobias Conradi (Talk) 04:21, 23 March 2006 (UTC)
I'm not sure how it would be written elsewhere but in the aviation field in Canada we use UTC-5(4). On the other hand some parts of some countries do not change for DST, Saskatchewan for example.
The US Naval Observatory addresses this issue in a manner of speaking. United States Code - Standard Time is the law (now a bit old, but without change on these points as of 2005-08-01). In 260a it states that the standard time of each zone when advanced by one hour shall also be the standard time of the zone. However, the USNO notes at the bottom of the page "Contrary to the exact wording of the above statute, Standard Time does not change with time of year. In practice, the time in effect (the Civil Time) is either Standard Time or Daylight-Saving Time." So take your pick, law or custom. By the way, US law does not mention UTC. Section 261 only mentions "mean solar time". — Joe Kress 06:29, 23 March 2006 (UTC)

Then I think I'd like to put it this way:

  • Standard Time in the U.S. Eastern Time Zone is Eastern Standard Time (EST), which corresponds to UTC-5. During daylight saving, the Eastern Time Zone observes Eastern Daylight Time (EDT), which corresponds to UTC-4.

How does this sound? --Uncle Ed 16:36, 23 March 2006 (UTC)

Clear and unambiguous can you change it to something more confusing. CambridgeBayWeather (Talk) 16:52, 23 March 2006 (UTC)

[edit] Zones and offsets

Based on this, I think I have identified a confusion between "time zones" (letters Z, A-M & N-Y) and "UTC offsets". But it's a natural error, especially for those people living in countries which do not observe Daylight Saving Time.

Most of the world, most of the time, observes standard time. But from spring to "fall" in most of the Northern Hemisphere and some of the Southern Hemisphere, "daylight saving" is observed. This advances local time from "standard time" to "daylight time".

This distinction is rather clear in the continental USA. The four major time zones are: Pacific (on the West coast, Mountain (centering on Colorado and the Rocky Mountains), Central (see Chicago), and Eastern (like New York). In each of these time zones, there is a corresponding standard and "daylight" time:

Time Zone Standard Time Daylight Saving Time
Pacific Pacific Standard Time Pacific Daylight Time
Mountain Mountain Standard Time Mountain Daylight Time
Central Central Standard Time Central Daylight Time
Eastern Eastern Standard Time Eastern Daylight Time

Many if not most of the articles confuse "standard time" with "time zone", as if there were something called, e.g., the "Mountain Standard Time Zone". Actually, USA has its "Mountain Time Zone" which observes Mountain Standard Time (MST) just a bit less than it observes Mountain Daylight Time (MDT).

When telling time in the US, we sometimes mention the time zone, especially if it's an event like a TV broadcast or a long-distance call which bridges time zones.

  • "9 o'clock Eastern, 8 Central"

To avoid confusion between standard time and daylight saving time, we often use abbreviations like EST (Eastern Standard Time) or EDT (Eastern Daylight Time). --Uncle Ed 20:12, 23 March 2006 (UTC)

This would tend to apply to Canada also. Also don't forget that most time zone maps are not correct as countries tend to put certain areas based on communications etc in the "wrong" time zone. CambridgeBayWeather (Talk) 20:52, 23 March 2006 (UTC)
One could say: "In summer the Mountain Standard Time Zone shrinks to more or less the size of Arizona." Tobias Conradi (Talk) 23:14, 23 March 2006 (UTC)
The problem is that it really should be called Mountain Time Zone. Which I guess makes everbody in the world (except me) wrong. I always live in the Mountain Standard Time Zone and I always set my clock to Mountain Time sometimes Mountain Standard Time and sometimes to Mountain Daylight Time. Also, has anybody ever seen a accurate time zone map? Even the CIA one has errors. CambridgeBayWeather (Talk) 06:50, 24 March 2006 (UTC)
Correctly speaking you never have your time at MT, you either have MST or MDT. MT would only be shorthand for these, or a collective term. Thus MTZ never shrinks while MSTZ and MDTZ fluctuate. (MDTZ has area of 0 km2 in winter. In summer MTZ splitts into two.)
Arguably, the following Time Zones exist within the US:
Zone Name Abbrev.    Winter  Summer  Notes
Guam      GST-10         UTC+10
Atlantic  AST4           UTC-4       PR, VI
Eastern   EST5EDT    UTC-5   UTC-4   
Central   CST6CDT    UTC-6   UTC-5
Mountain  MST7MDT    UTC-7   UTC-6
Arizona   MST7           UTC-7       Excludes the Navajo Nation
Pacific   PST8PDT    UTC-8   UTC-7
Alaska    AKST9AKDT  UTC-9   UTC-8   Mainland and Eastern Aleutian Is.
W.Aleut.  HAST10HADT UTC-10  UTC-9   
Hawaii    HAST10         UTC-10      Some sources say 'HST'
AmSamoa   ASST11         UTC-11
where the term "Time Zone" refers to the geographic areas which by law have the same time as one another by the same rules. That means that. The MST7MDT states do not "change zones" when going on and off Daylight Saving Time; they are a zone unto themselves. Nor do AZ and the tropical islands go anywhere when they do not.
...But I'm not comfortable with that definition. Alternatively, AZ is part of the MTZ, and HI is part of the HATZ, but represent separate entities according to some other word that I can't put my finger on.The Monster 21:54, 9 March 2007 (UTC)
Or the whole structure needs to be changed. One could also call the DSTs standard time, actually these times are standardized too. Tobias Conradi (Talk) 22:32, 24 March 2006 (UTC)
The DSTs are standardized but not "standard". That name already means something different.The Monster 21:54, 9 March 2007 (UTC)

Our work on this topic borders on "original research". I don't think people have thought too deeply about this before. Every encyclopedia made in English prior to Wikipedia has been British or American. Now people all over the world, include non-native speakers of English, are contributing. This gives the English-language Wikipedia an international flavor.

Let's keep working on this - together! :-) --Uncle Ed 15:42, 24 March 2006 (UTC)

[edit] Time zone is an ambiguous term

I think that perhaps a lot of the confusion people have is that the term "time zone" is unfortunately overloaded with at least two different meanings. In the pure sense it is defined mostly by just a fixed offset from UTC (and the civil authority which names it). However the same term is also used when talking about a homogeneous region that always observes the same local time (but which isn't necessarily fixed to any meridian). So in a bigger sense your time zone depends upon your location as well as, paradoxically, the time. I have never seen a clear or lucid description of this, nor have I ever seen different terminology which is badly needed.

Furthermore it's not just Daylight Savings/War Time that causes the observed timezone to not be fixed. Historical and/or civil changes also do that. So it's easy to argue that even though the city of Detroit today observes the same local time as say Cleveland, historically that has not always been the case. So from a history-preserving perspective Detroit is a different timezone. And even a change in the rules, such as the Energy Policy Act of 2005 which will change the daylight rules for the whole US next year. Defining a "time zone" as a region throughout which the local observed time is always the same is what the zoneinfo-style cateogrization does. I guess I see probably three definitions: 1) an offset from UTC (an instantaneous? time zone), 2) a region which always observes the same local time according to current civil authority/practices (a legal time zone), 3) a region which has always observed the same local time under the same civil authority/practices (a geographic/historic time zone).

Is this type of clarification potentially useful? I don't want to invent new research here, but it seems that something needs to be said. Dmeranda 21:13, 24 March 2006 (UTC)

to use legal vs standard is IMO usefull. number 3 needs a better name. Dmeranda, thx for writing the tz article. :-) Tobias Conradi (Talk) 22:36, 24 March 2006 (UTC)
I agree, it's a fairly loosely defined term and it would be original research if we were to attempt to change that. I think the most useful way to describe them is to assign time zones to areas which share the same local time outside of any daylight saving period. This can be described as UTC+n. Then you can note which subset of those locations have a daylight saving time, give it a name if it has one but probably avoid writing UTC+m for it to avoid confusion. This seems to be pretty much standard practise including here on Wikipedia. I have a bit of a problem with the UTC+n notation (because not all localities use UTC as the base time, some still use GMT/UT1) but again this is something too entrenched to change, except perhaps by just dropping any prefix (e.g. +9 instead of UTC+9), which has some precedent.--Russell E 21:53, 25 March 2006 (UTC)

I would not drop the prefix as long as it is correct. Is there a list of countries using GMT based time ? Tobias Conradi (Talk) 01:50, 27 March 2006 (UTC)

The main reason I'd suggest dropping it uniformly is because otherwise you'd have a separate entry for UTC+6 and GMT+6 (for example)... but anyway I'm not really serious unless anyone else is.--Russell E 12:02, 27 March 2006 (UTC)
I still think it's worth a small paragraph near the top to discuss that the phrase "time zone" may mean different things, even if we don't try to fix the entrenched ambiguous terminology. I see too many people get confused. Perhaps just something as brief as: A time zone can represent a region where the local time is some fixed offset from a global reference (usually UTC), or a time zone can represent a region throughout which the local time is always consistent even though the offset may flutuate seasonally. - Dmeranda 22:28, 27 March 2006 (UTC)
Sounds good. Perhaps it would be helpful to craft in a link to Daylight saving time to clarify what is meant by "fluctuate seasonally".--Russell E 23:42, 27 March 2006 (UTC)
Okay, I went ahead and rewrote/reorganized much of the introduction to make it clearer and to flow better. The article still needs some further work, IMHO, but I'd like to get the introductory text suitable first. - Dmeranda 06:41, 28 March 2006 (UTC)

I didn't understand why you took this paragraph out:

In many parts of the world, countries or their internal subdivisions observe so-called "daylight saving time", advancing their clocks by an increment of typically one hour in early spring. See, for example, European Summer Time.

Your Edit Summary only said redundant, daylight saving was already discussed after the term is first defined but perhaps I overlooked the place where --Uncle Ed 18:25, 20 April 2006 (UTC)daylight saving was discussed.

No harm intended...It just seemed like extra information which was already discussed later in the article and adding clutter. Look in the second paragraph, and also search for the term for later occurances. This may just be an issue of placement though, and in general I don't object to the content of your addition. I just don't think it makes sense to discuss daylight or other zonal complexities until the fundamental definitions of time zone is itself discused. If you want though, perhaps write up a paragraph to be inserted later in the introduction section (instead of right at the top), or even better might be to combine it with the section on Offset Time Zones, describing how the actual local time zone often differs from the pristine so-called standard time zones. Such a cleanup would probably be quite welcome. -- Dmeranda 18:51, 20 April 2006 (UTC)

Thanks for explaining that. I've been doing two things with time offsets and time zones since spring began:

  • Creating templates which help readers find out what the current local time is
  • Re-organizing the dozens of timezone-related articles

Perhaps you'd like to join Wikipedia:WikiProject Time Zones. --Uncle Ed 19:54, 20 April 2006 (UTC)

[edit] European Time Zones

A close look at the time zone map shows that geographically UTC+1 ends at the western boarderline of Germany and Switzerland. The Netherlands, Belgium, Luxembourg, France and Spain - all currently using UTC+1, should be in time zone UTC+0 together with the UK. On the other hand, Republic of Ireland, Iceland, Portugal and a number of Arican states (currently all in UTC+0 together with the UK) should be in time zone UTC-1. Why do these countries use such a shift? --Gazibara 23:12, 29 April 2006 (UTC)

The Netherlands, Belgium, Luxembourg, France and Spain - all currently using UTC+1, should be in time zone UTC+0 together with the UK. - Why should they? Tobias Conradi (Talk) 12:38, 18 May 2006 (UTC)
I assume (s)he means because of their geographical location. The answer's mostly traditions, customs, and quirks of history, I'd wager. —Nightstallion (?) 13:14, 19 May 2006 (UTC)
or easiness in daily life / efficiency. Not every country in the world uses county by county rules. (or even smaller areas). The other way: All Continental US could use one zone like it is done in China. :-) Tobias Conradi (Talk) 00:03, 20 May 2006 (UTC)
Agree with Tobias, the convenience of having a common Time Zone exceeds the inconvenience of having a slightly artificial time. European countries used to have different summer time rules, and some did not observe it all, result: confusion. Now there are a Europe wide standard changeover dates.TiffaF 11:03, 28 August 2006 (UTC)

From memory: Portugal tried going to CET for a few years, but gave up as it was too artificial, so there is again a time change between Portugal and Spain. Britain experimented with "permanent summer time" in the 1970's. In the winter Britain was the same as France, but not in the summer. It was given up because of complaints mostly from Scotland. In winter, it didn't get light until 10:00, which was deemed too dangerous for children going to school. TiffaF 11:03, 28 August 2006 (UTC)

[edit] I'm probably wrong but...

Wasn't it a canadian who came up with the whole idea of having time zones? On the canadian pacific railroad they had to keep checking the time by the position of th sun, then this guy thought of time zones. If I'm right someone should mention this, if I'm wrong, well shoot me :p. Or is it mentioned already? If it is I didn't see it... —Preceding unsigned comment added by 24.85.165.59 (talk)

Sir Sandford Fleming's suggestion of time zones for the entire world is discussed in the fifth paragraph of Time zone#history. However, four time zones for just the United States were suggested by Charles F. Dowd over a decade earlier, as discussed in the fourth paragraph. — Joe Kress 05:13, 13 June 2006 (UTC)

[edit] Correct Writing Format for Time Zone

Exactly what is the correct writing format for a certain time zone? Take Pacific, Central and Eastern Time Zones. There's ST and DT, standard time and daylight time. I've notice some articles on people's blogs, news articles and other internet-based articles that they use PDT, PST or simply PT. Not to mention, each site sticks to one format(e.g. PDT) while the other simply uses another(e.g. PT)

Is there's some kind of general format for the time zones? --HighEnergyProtons 13:24, 8 July 2006 (UTC)

In general, when a scheduled time is the same whether it is in standard time or in daylight time, then standard or daylight are often not used. Thus if the evening news cast on television is at 6 p.m. in both summer and winter, then the scheduled time may simply state 6 p.m. ET (Eastern Time). Three letter abbreviations for time zones, at least in the United States, are unofficial only—they are not officially sanctioned or even mentioned in United States law (only full words are used in the applicable laws). — Joe Kress 00:26, 9 July 2006 (UTC)
For most time zones there is no official standard, but instead just de facto standards which may even be ambiguous or conflicting. As you've noticed this practice commonly leads to confusion, and is why it's a good idea for blogs and news websites to always use UTC or formats such as ISO_8601. For copyedit work you may also refer to The Chicago Manual of Style section 8.96 (edition 15) for further writing style guidance. --- Except for some of the international standard abbreviations like UTC, the definition and naming of time zones varies country by country usually by national legislation. Rarely though are initialisms for time zones so defined. Perhaps the best source of information about the various time zones, their common initialisms and history is to read through the text files that make up the zoneinfo database (there is especially a lot of wealth of knowledge in the comments in the tzdata source files). Within the US the names of time zones is set by US Code, specifically 15 USC 263, but no initialisms are mentioned. Capitalization follows standard English rules, so it's "Pacific standard time", but just "eastern standard time". Interestingly, even though daylight is observed separate names like "eastern daylight time" are not codified in law, just the "standard" names. And if you go back to the World War II era, you'll even find reference to ?WT and ?PT, for war and peace time. If you're dealing with other countries, you need to refer to their specific authority. -- Dmeranda 06:13, 9 July 2006 (UTC)

[edit] Confusion over offsets

It seems there is some confusion in the Nautical portion of this article. The article states that the "offset" is used with the string "UTC" to denote a timezone, and it states that the offsets are positive to the west of the prime meridian and negative to the east of the prime meridian. At the end of the same paragraph, it states that South Africa is on "UTC+2" time. Shouldn't it be "UTC-2" time, since South Africa is east of the prime meridian? Throughout the article, "UTC+<number>" is given for US timezones as well.

Yes, the offset of nautical time zones and standard time zones are negatives of each other. However, nautical time zone descriptions (from what I know) do not use names of the format "UTC+/-nn", those are for standard time zones. So the inclusion of the UTC+2 link in that paragraph is both ripe for confusion and unnecessary...especially since the whole point it is making is about the name "Zulu", and not about the offset number. I will go ahead and fix that. However I still find the whole section could use even more clarity in the writing.--Dmeranda 20:38, 14 July 2006 (UTC)
I just removed the entire sentence containing the South Africa Time reference, finding it was more confusing than useful. Except for that sentence, I wrote the entire section "Nautical time zones", so I am responsible for any lack of clarity. — Joe Kress 02:36, 15 July 2006 (UTC)

[edit] Time zone table

I found this table on another site (credited at the end of the table), and I was wondering just how many of those redlinks should be made redirects, which should be ignored, and where the table can be placed (if anywhere).
—Lady Aleena talk/contribs 23:44, 30 July 2006 (UTC)

Abbreviation Time Zone Location(s) UTC
A Alpha Time Zone Military UTC+1 hour
ACDT Australian Central Daylight Time Australia UTC+10:30 hours
ACST Australian Central Standard Time Australia UTC+9:30 hours
ADT Atlantic Daylight Time North America UTC-3 hours
AEDT Australian Eastern Daylight Time Australia UTC+11 hours
AEST Australian Eastern Standard Time Australia UTC+10 hours
AKDT Alaska Daylight Time North America UTC-8 hours
AKST Alaska Standard Time North America UTC-9 hours
AST Atlantic Standard Time North America UTC-4 hours
AWST Australian Western Standard Time Australia UTC+8 hours
B Bravo Time Zone Military UTC+2 hours
BST British Summer Time Europe UTC+1 hour
C Charlie Time Zone Military UTC+3 hours
CDT Central Daylight Time North America UTC-5 hours
CEDT Central European Daylight Time Europe UTC+2 hours
CEST Central European Summer Time Europe UTC+2 hours
CET Central European Time Europe UTC+1 hour
CST Central Summer(Daylight) Time Australia UTC+10:30 hours
CST Central Standard Time Australia UTC+9:30 hours
CST Central Standard Time North America UTC-6 hours
CXT Christmas Island Time Australia UTC+7 hours
D Delta Time Zone Military UTC+4 hours
E Echo Time Zone Military UTC+5 hours
EDT Eastern Daylight Time North America UTC-4 hours
EEDT Eastern European Daylight Time Europe UTC+3 hours
EEST Eastern European Summer Time Europe UTC+3 hours
EET Eastern European Time Europe UTC+2 hours
EST Eastern Summer(Daylight) Time Australia UTC+11 hours
EST Eastern Standard Time Australia UTC+10 hours
EST Eastern Standard Time North America UTC-5 hours
F Foxtrot Time Zone Military UTC+6 hours
G Golf Time Zone Military UTC+7 hours
GMT Greenwich Mean Time Europe UTC
H Hotel Time Zone Military UTC+8 hours
HAA Heure Avancée de l'Atlantique North America UTC-3 hours
HAC Heure Avancée du Centre North America UTC-5 hours
HADT Hawaii-Aleutian Daylight Time North America UTC-9 hours
HAE Heure Avancée de l'Est North America UTC-4 hours
HAP Heure Avancée du Pacifique North America UTC-7 hours
HAR Heure Avancée des Rocheuses North America UTC-6 hours
HAST Hawaii-Aleutian Standard Time North America UTC-10 hours
HAT Heure Avancée de Terre-Neuve North America UTC-2:30 hours
HAY Heure Avancée du Yukon North America UTC-8 hours
HNA Heure Normale de l'Atlantique North America UTC-4 hours
HNC Heure Normale du Centre North America UTC-6 hours
HNE Heure Normale de l'Est North America UTC-5 hours
HNP Heure Normale du Pacifique North America UTC-8 hours
HNR Heure Normale des Rocheuses North America UTC-7 hours
HNT Heure Normale de Terre-Neuve North America UTC-3:30 hours
HNY Heure Normale du Yukon North America UTC-9 hours
HST Hawaii-Aleutian Standard Time North America UTC-10 hours
I India Time Zone Military UTC+9 hours
IST Irish Summer Time Europe UTC+1 hour
K Kilo Time Zone Military UTC+10 hours
L Lima Time Zone Military UTC+11 hours
M Mike Time Zone Military UTC+12 hours
MDT Mountain Daylight Time North America UTC-6 hours
MESZ Mitteleuropäische Sommerzeit Europe UTC+2 hours
MEZ Mitteleuropäische Zeit Europe UTC+1 hour
MST Mountain Standard Time North America UTC-7 hours
N November Time Zone Military UTC-1 hour
NDT Newfoundland Daylight Time North America UTC-2:30 hours
NFT Norfolk (Island) Time Australia UTC+11:30 hours
NST Newfoundland Standard Time North America UTC-3:30 hours
O Oscar Time Zone Military UTC-2 hours
P Papa Time Zone Military UTC-3 hours
PDT Pacific Daylight Time North America UTC-7 hours
PST Pacific Standard Time North America UTC-8 hours
Q Quebec Time Zone Military UTC-4 hours
R Romeo Time Zone Military UTC-5 hours
S Sierra Time Zone Military UTC-6 hours
T Tango Time Zone Military UTC-7 hours
U Uniform Time Zone Military UTC-8 hours
UTC Coordinated Universal Time Europe UTC
V Victor Time Zone Military UTC-9 hours
W Whiskey Time Zone Military UTC-10 hours
WEDT Western European Daylight Time Europe UTC+1 hour
WEST Western European Summer Time Europe UTC+1 hour
WET Western European Time Europe UTC
WST Western Standard Time Australia UTC+8 hours
X X-ray Time Zone Military UTC-11 hours
Y Yankee Time Zone Military UTC-12 hours
Z Zulu Time Zone Military UTC
From Time Zone acronyms and abbreviations

maybe place at List of time zone abbreviations. Should be said why some French and German is included. Tobias Conradi (Talk) 00:59, 31 July 2006 (UTC)

[edit] Newer Map?

This map is already out of date. Sri Lanka for instance is now no longer 6 hours ahead of UTC. —Preceding unsigned comment added by 128.61.98.24 (talk) 00:30, 14 August 2006

Yeah, it even says that some time zones have changed. Is it so hard to make a new map? --The monkeyhate 19:57, 5 February 2007 (UTC)
If somebody can compile a list of changes required, I may have the time to do it. The map was made at the end of 2005. But I will be pain in the ass asking questions about DST rule on obscure places. --ChoChoPK (球球PK) (talk | contrib) 21:13, 5 February 2007 (UTC)
There is an SVG version of the 2007 World Factbook Time zone map here. It should be easier to edit than a raster PNG or GIF etc.--Trounce 16:34, 22 February 2007 (UTC)

[edit] Where the Nautical TimeZones Are

One thing that isn't always clear to people looking at the timezone map -- the nautical time zones do not start at 0, 15, 30, 45, 60, degrees, etc.

The Greenwich time zone runs from 7.5°W to 7.5°E, so successive nautical time zones are at 22.5, 37.5, 52.5, 67.5, 82.5, 97.5, 112.5, 127.5, 142.5, 157.5, 172.5 both to the East and West of the Greenwich Prime meridian.

Before the use of GPS was common, any mariner who got confused on this point could get confused about where the ship was, since celestial navigation depends on knowing the time.

So I added a couple of lines to the discussion of Nautical Time Zones.

--SV Resolution(Talk) 18:34, 24 August 2006 (UTC)

[edit] Japanese text?

Just a minor edit, but in the history section, there was some Japanese text that really didn't belong (although I don't know what it means, the article is in English, anyway). If anyone can translate it, then put it back and just disregard this comment.

This hodgepodge ended when Standard zone time was formally adopted by the U.S. Congress on 19 March 1918. いやな事ばかり Time zones were first proposed for the entire world by Canada's Sir Sandford Fleming in 1876 as an appendage to the single 24-hour clock he proposed for the entire world (located at the center of the Earth and not linked to any surface meridian!).

Thanks, Torpov 03:20, 5 September 2006 (UTC)

That text was added by an anonymous editor (124.26.191.50) on 2 September 2006 and only partially reverted by Malrase. Thanks for completing the reversion. — Joe Kress 02:22, 6 September 2006 (UTC)

[edit] Politically correct Map?

Interesting how the map wishes to be politically correct by listing who claims what territory, does this really belong on a timezone map? Imho it belongs on a political map. If we are going for such niceties, then I'd suggest that the bounderies of Tibet (pre-occupation) are also added. After all the country was invaded and is still illegally occupied by a foreign army. No-one recognizes the annexation. As a matter of fact the legal government in exile of Tibet may have set another time zone (I suspect they would not be using Beijing time). So the legal time zone and de facto occupation time zone may be different. —Preceding unsigned comment added by 213.35.237.178 (talk)

The map is an extension of the CIA map "Standard Time Zones of the World" (pdf, 680KB). Obviously, the CIA thought that those remarks did belong on a time zone map. Because the CIA map is the basis of the Wikipedia map, all borders are those officially recognized by the United States. The CIA map is one of the few that is in the public domain and hence does not have any copyright restriction. Most maps are copyrighted and hence are forbidden on Wikipedia. Anyone is welcome to create their own map, but it must be their own creation with no copyright or be in the public domain. You cannot take a copyrighted map and simply add the boundaries of Tibet to it—that would violate the original copyright. Before the creation of the People's Republic of China in 1949, most of Tibet was in the GMT+6 time zone along with parts of Sinkiang, Tsinghai, Sikang, and Outer Mongolia under the nominal control of the Republic of China (using Wade-Giles romanizaton). See Time in China. — Joe Kress 16:25, 12 September 2006 (UTC)

[edit] Before Time Zones

I think the article could be more clear about how local time operated before time zones came into use. In the United States, for instance, was everyone on the same time prior? If not, how were local times established? Sylvain1972 12:24, 15 October 2006 (UTC)

Yes, the last two paragraphs of the introduction could be worded better. Originally, every city had a different time, the time displayed on a sundial (corrected for the equation of time). Thus with hundreds of cities, the United States alone could have had hundreds of times except that cities north-south of each other had the same time. — Joe Kress 06:46, 16 October 2006 (UTC)

[edit] Quick question...

What is the abbrieviation for the zone Wikipedia's servers are in? I can't remember whether it is California or Florida and I can't for the life of me find it. Lady BlahDeBlah 17:44, 28 October 2006 (UTC)

According to Wikipedia, its main servers are in Tampa, Florida, with additional servers in Amsterdam and Seoul. The statement in History of Wikipedia#Beginnings of a new project that its server (singular?!) is in San Diego, California, appears to be historical. — Joe Kress 07:19, 30 October 2006 (UTC)

[edit] DUT

DUT is refered to in the article, but it is not defined/explained. David Broadfoot 13:51, 9 November 2006 (UTC)

It may not be defined, but it is linked. Click on the link for the definition. The definition is a bit too complex to include here for such a minor portion of the article. — Joe Kress 21:01, 9 November 2006 (UTC)

[edit] External link removed

  • http://www.radicalcartography.net/?timezoneslow - Animated time zones - Shows the relationship between arbitrary time zones and "natural" zones.

I removed this non-commercial external link because the page required Flash and because the content seemed unintuitive. I understand that it's showing each of the timezones in black and each of the "natural" time zones in gray but that wasn't very obvious. Of the three links that I removed, it was the only one that seemed that it might be useful. ~a (user • talk • contribs) 15:25, 20 December 2006 (UTC)

[edit] exteranal links

I've added the link wich was removed by Arichnad. It's a usefull link for a website on the topic of the article, it features quality content which could not be recreated at wikipedia pages, and it is useful for useres who are looking for the time zones invormation. —The preceding unsigned comment was added by Oleksiy.n (talk • contribs) 12:27, 22 December 2006 (UTC).

Sorry for the late response Oleksiy. In the past I've removed the two links to: 24timezones.com and qlock.com. I won't remove them again until I get other editors to agree that they fail WP:EL. Please weigh in. ~a (user • talk • contribs) 05:27, 27 December 2006 (UTC)
I think these (and a few of the others) should be removed per WP:EL. Grouse 16:53, 28 December 2006 (UTC)

[edit] WikiProject CCT

hear ey! Hear ey! The WikiProject CCT is now open for new recruits. If you are interest in Current City Time please give us a visit at WP:CCT. --CyclePat 00:03, 14 January 2007 (UTC)

[edit] UTC± Notation

If the notation for a time range five hours ahead of UTC is UTC+5, then shouldn't the notation for five hours behind be UTC−5, not UTC-5? It seems like it should be a minus, not a hyphen, for consistency. 155.33.61.98 20:04, 14 February 2007 (UTC)

I agree that we should use a minus sign, except that UTC-5 has the minus sign, while UTC−5 has a hyphen. --ChoChoPK (球球PK) (talk | contrib) 05:04, 15 February 2007 (UTC)
The hyphenated negative forms, like UTC-5, were created when special characters, like the minus sign, were not allowed in article titles by Wikipedia software. But now that special characters are allowed, the "proper" form UTC−5 is allowed. I noted that a few minus versions did not have redirects to their hyphenated articles, so I created those redirects. (The anonymous editor did use the correct signs.) — Joe Kress 06:55, 15 February 2007 (UTC)

[edit] 1st country to celebrate New Years

I was watching The Weakest Link and Anne said that some town in New Zealand celebrated new years 1st. But looking at the time zone map, it seems that there are quite a few places that actually see the New Year in before NZ. Can anyone offer any explanations? --nocturnal omnivorous canine 12:17, 3 March 2007 (UTC)

This kind of TV show is usually not very rigorous on details like this. Nor are the maps on the complimentary magazines found on many airlines. --ChoChoPK (球球PK) (talk | contrib) 23:22, 3 March 2007 (UTC)
Actually New Zealand is one of the first, but not the first. The Line Islands in Kiribati has time zone UTC+14 and celebrates new year first. But it has only 8000 inhabitans and introduced this time zone in 1995, and many tables and maps have not been updated. Actually our map in this article is wrong too. The Chatham Islands has UTC+13¾ in December and 600 inhabitants and comes after the Line Islands.
New Zealand has UTC+13 in December (and UTC+12 in July) and is one of the first. Tonga celebrates new year at the same time as NZ. Only the Line Islands and Chatham Islandsare before. Many maps and tables do not include daylight saving time info, becasue it would make it more complicated. But the entire NZ (and Tonga) has new year at the same time, because it is based on official time. So Gisborne is not earlier than the rest of New Zealand. -- BIL (talk) 12:29, 22 February 2008 (UTC)

[edit] Map

The map was recently changed from Image:Timezones_optimized.png to Image:2007-02-21 time zones-white.png. The first map was based from a 2005 edition of the CIA map, with the necessary corrections according to the content of Wikipedia. Now it's 2007, the first map is somewhat out of date, such as Sri Lanka, but the second map, CIA's 2007 edition not only continues to have the errors carried from 2005, it has not made the necessary updates to reflect recent changes. So I reverted. --ChoChoPK (球球PK) (talk | contrib) 02:13, 1 April 2007 (UTC)

Someone replaced the 2005 map with CIA's outdated version again. I made an updated version of the map which reflects all changes made and scheduled up to June 2008, and included it in the article. I did not include DST information on the map as the 2005 version did, perhaps I will do that later. I have noticed that it is almost impossible to find an updated world map of time zones, commonly found maps are usually very old. CIA's 2007 map, for example, still shows Sudan in UTC+2, but it moved to UTC+3 in 2000. Dave (talk) 20:50, 28 May 2008 (UTC)

I reccomend that you at least change the CIA date at the lower right from 3-05. You might also change the other code numbers at the lower right to something else indicative of your update. — Joe Kress (talk) 02:19, 29 May 2008 (UTC)

[edit] Linux is Unix-like, not Unix based.

In paragraph Unix, it says that "Most Unix based systems, including Linux and Mac OS X, keep system time as UTC (Coordinated Universal Time)." Though Linux is Unix-like, not unix based. "Linux (IPA pronunciation: /ˈlɪnʊks/) is a Unix-like computer operating system family." [[2]]

"A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification."[[3]] --Natasha2006 12:27, 10 April 2007 (UTC)

[edit] 50 hours

Because the earliest and latest time zones are 26 hours apart, any given calendar date exists at some point on the globe for 50 hours. For example, 11 April begins in time zone UTC+14 at 10:00 UTC 10 April, and ends in time zone UTC-12 at 12:00 UTC 12 April.

Could someone please explain what the author(s) of the above are trying to say? Do they mean "When it's 10:00 UTC 10 April in time zone UTC+14, it's already 11 April somewhere else in the world, and when it's 12:00 UTC 12 April in time zone UTC-12, it's still 11 April somewhere else in the world"? The way it's currently written, it seems to be saying that 11 April begins on 10 April and ends on 12 April - which confuses the hell out of my brain. -- JackofOz 01:27, 6 June 2007 (UTC)
What you said is correct. The first place to get April 11 is the time zone of UTC+14. This means at UTC time it is 14 hours earlier, 10 AM the day before. Now the last place to change from April 11 to April 12 is UTC zone -12. Which is 12 hours laster than UTC (12 noon). All it means is, if you travel to the right places fast enough, because of the time zones you could technically spend up to 50 hours with the single date of April 11 - a jet lag of some 26 hours!--Dacium 02:37, 6 November 2007 (UTC)

[edit] Blatant Error

As described above, there is a glaring faux pas in this article.

"April 11 begins in time zone UTC+14 at 10:00 UTC April 10, and ends in time zone UTC-12 at 12:00 UTC April 12."

WRONG!! If the time is 04/11 00:00 at UTC-12, then the time at UTC+0 is 12 hours later, obviously at 04/11 12:00, not 36 hours later as the article would have me believe. Miqrogroove 00:01, 27 June 2007 (UTC)

In time zone UTC-12, 4/11 ends at 0:00 4/12 local time (the first second of 4/12). So that very time point is 12:00 UTC April 12. The statement in the article is not wrong. --ChoChoPK (球球PK) (talk | contrib) 00:42, 27 June 2007 (UTC)
I will grant you that point, however the existing article doesn't make sense. I recommend saying "April 11 begins in time zone UTC+13 at 11:00 UTC April 10, and April 12 begins in time zone UTC-12 at 12:00 UTC April 12."
Furthermore, I would like to point out the UTC+14 timezone does not appear anywhere on the updated CIA map. This article may be stale. —Preceding unsigned comment added by Miqrogroove (talk • contribs) 00:56, 27 June 2007
I believe the original intent is "A local April 11 can span 50 hours globally". Regarding UTC+14, I believe Kiribati changed its time zone so that they were the first to enter the third millennium. The article Kiribati says so. The CIA map is known to be inaccurate. --ChoChoPK (球球PK) (talk | contrib) 01:18, 27 June 2007 (UTC)
The third millennium began 6.5 years ago. Perhaps they switched again? Miqrogroove 02:11, 27 June 2007 (UTC)
According to the comments in the most recent zoneinfo file for Kiribati, that nation changed it time zones so that the entire country has a uniform date as of 1995-01-01. This created the UTC+14 time zone, and as far as I can tell, Kikibati hasn't made any subsequent changes to its time zones. The zone info comment cites the Wall Street Journal, page 1, 1996-01-22. Scott Roy Atwood (talk) 03:17, 22 February 2008 (UTC)

[edit] DST nonsense

removed: The tendency to draw time zone boundaries far to the west of their meridians allows greater utilization of more daylight in the afternoon hours. - The use of daylight is INDEPENDET of clock time! TimeXCode 20:52, 1 September 2007 (UTC)

Its not indepedant. Most countries have fixed work hours (9am to 5pm for example), moving the zone boundaries west and establishing it on that point creates more daylight after work has completed. By your logic everyone should just use UTC no matter where they are because day/night time is indepedant of clock time...--Dacium 02:33, 6 November 2007 (UTC)

[edit] IST

IST is not calculated at Mumbai, Maharashtra, it is calculated at Allahabad, Mirzapur Uttar Pradesh. --Rsrikanth05 (talk) 11:42, 18 November 2007 (UTC)

[edit] What is the world's last time zone?

Would anybody be nice enough to tell me what is the world's last time zone? I would really like to know what it is. Thanks.

Best wishes,

Albert —Preceding unsigned comment added by Albert Cheng (talk • contribs) 21:26, 6 December 2007 (UTC)

I assume you are asking what is the time zone with the greatest westward offset from GMT time. According to the article, GMT-12 is the last time zone, but uninhabited Baker Island and Howland Island are the the only landmasses there. According to the 2007g version of zoneinfo, GMT-11 is the westernmost inhabited timezone, and it is shared by Midway Island, Niue, American Samoa, and Samoa. Scott Roy Atwood (talk) 20:09, 19 February 2008 (UTC)
Albert may also mean the most recently added time zone. That would be UTC–4:30 added on December 30, 2007 by and for Venezuela. But because we are answering his query late, the next most recent was UTC+14 created by Kiribati for its Line Islands in the central Pacific by skipping December 31, 1994. Not counted are boundary shifts of previously existing time zones and Daylight saving time. — Joe Kress (talk) 01:01, 21 February 2008 (UTC)

[edit] Useful time zone table?

Does anyone have any use for this table? I made it, but I don't have any use for it now. - LA @ 07:40, 18 February 2008 (UTC)

[edit] New South Wales and Java

In the section on Java, there is a paragraph that talks about problems caused by time zone changes introduced by New South Wales for the 2000 Olympics. It is not at all clear from the context what exactly the problem is, or what relevance it has to Java. Did it cause all time zones in Java to change there DST start/end dates? Was the problem that OS and Java time zone defintitions would be out of sync? And if so, wouldn't that be the case any time anybody changes time zone definitions, which happens very frequently? What is special out that particular time zone change?

I'm strongly inclined to remove that entire paragraph, because it doesn't appear to add any value to the page. Please let me know if you disagree. Scott Roy Atwood (talk) 20:51, 27 March 2008 (UTC)

[edit] Scope of this Article

I came to this article wanting to know where the boundary between Eastern Time and Central Time is, not because I wanted to know how SmallTalk handles time. I'm thinking that moving all of the computer timezone handling information to a separate article would probably make sense, and having detailed time zone maps in this article, and or table(s) with links to the articles about the individual time zones, would probably improve this article. JNW2 (talk) 16:49, 16 April 2008 (UTC)

I suspect the computer time zone info should probably remain here, but I have no strong opinion on that. Much of your request for details on individual time zones is a result of splitting off List of time zones from this article. Your requested links are in that article. I'm adding a dab link at the head of the article to cover requests such as yours. — Joe Kress (talk) 21:02, 16 April 2008 (UTC)

[edit] Time zones at the poles?

I came to this page looking for information about the treatment of time zones at the poles, but didn't find a satisfactory answer. There is a little bit about conventions in Antarctica, but one the web there seem to be claims that it generally uses UTC+0. Does this give scientists any troubles? Are there accounts of explorers moving from time zone to time zone with single steps? ---Jake (talk) 23:22, 25 April 2008 (UTC)

The research base at the South pole use New Zealand time, like the McMurdo base. The supplies to the South pole usually comes from New Zealand. The research bases on the Antarctic penisula usually have Chilean or Argentinian time zone. The rest use varying time zones. This info was listed in List of time zones. The North pole has no official time zone, since it is at sea and has no longitude. Visiting ships and planes usually use the time zone of their departure port/airport. --BIL (talk) 20:49, 26 April 2008 (UTC)

[edit] Database of timezone boundaries?

Anyone care to post a link to some kind of table/database that maps longitude/latitude coordinates to time zones? For finding what timezone a place is in?

E.G. something like

<Latitude> <Longitude> <Timezone> for each latitude(rounded down to 1 decimal point?)? And then it would be selected by something like

select Timezone from Table where Latitude=round(LocationLatitude,1) order by abs(Longitude-LocationLongitude) limit 1

??


Thanks in advance :) this is very important since just doing round(LocationLongitude/15) is useless thanks to the timezone boundaries being completely warped by political territories and stuff. —Preceding unsigned comment added by 67.53.37.218 (talk • contribs)

I know of no such database. It would be very difficult to construct, especially near the time zone boundary, because zones within multi-zone countries are specified by the political subdivisions of the country, which can be natural features like rivers or mountain ranges or even surveyed lines. For an example of this complexity see the definition of the boundary between the central and mountain time zones of the United States in 49CFR71.7 (T means township and R means range, the borders of survey townships E-W or N-S of a specific surveyed point). — Joe Kress (talk) 19:16, 4 June 2008 (UTC)