Talk:List of UTC offsets

Untitled

Does anyone know how the :30 and :45 time zones affect the presence of a certain hour?no

For instance, if it is noon GMT, will it be noon in Alaska nine hours later (9:00GMT) and then noon in French Polynesia a half-hour after that (9:30GMT)?--99.251.89.115 (talk) 21:51, 19 October 2008 (UTC)sara

If so, it seems that a particular moment on a particular day will actually happen 39 times. Is this actually the case?

Thanks. — Preceding unsigned comment added by 69.132.36.24 (talk) 16:11, 4 April 2006 (UTC)

Featured list?

This is a pretty nice list. If we add some references, we should nominate it as a featured list. Chanheigeorge 23:20, 3 May 2006 (UTC)

When this list was split off from time zone, the principal written references were left behind, the CIA and NAO maps. Even so, they are usually badly outdated, taking as much as ten years to reflect changes made by any government. Thus, individuals in the affected countries are much more important than any written source. This is contrary to the references cited by most articles which must be published. — Joe Kress 05:30, 15 May 2006 (UTC)

I second that, I was looking to nominate it just now, but I see there's unresolved issues. I'll be working on getting some corroborative sources over the next couple of days. Cheers Festrilmongrit (talk) 15:29, 18 June 2009 (UTC)

This source looks pretty detailed: Time Genie. Chanheigeorge 22:57, 4 May 2006 (UTC)

At first glance, Time Genie appears to get its information from Wikipedia, which it cites for more information. It even lists its 'countries' with Wikipedia idiosyncracies, such as alternative names. Furthermore, Time Genie does not give any time zone info—it only gives the current time in the selected country, from which the reader has to mentally derive the time zone. — Joe Kress 05:30, 15 May 2006 (UTC)

how do you come to the conclusion that tg may get the info from wp? Tobias Conradi (Talk) 01:24, 23 May 2006 (UTC)

Arctic and Antarctica

Does anyone know what time is used in Arctic and Antarctica? Dali 19:09, 19 June 2007 (UTC)

Each country in the Arctic determines its own time. Antarctic stations generally keep the time of their supply bases. For example, the Amundsen-Scott South Pole Station keeps New Zealand time, including its daylight saving time of UTC+13 in the southern summer, even though all ideal time zones converge at the South Pole. — Joe Kress 04:28, 21 June 2007 (UTC)

GMT to PST

So if someone told me to call them at 9 PM in England, does that mean 1 PM in California or 2 PM? Thank you. 71.243.206.213

California has UTC-8 and UK has UTC (both with daylight saving time), so the time difference is 8 hours most of the year. 9 PM in England is 1 PM in California. This is not valid around the time of start and stop of daylight saving time. Then it is hard to calculate it, see Daylight saving time around the world. -- BIL 07:23, 5 August 2007 (UTC)

Principal cities

Great idea, but does every single time zone need four representative cities listed? One for Nepal, Afghanistan, etc. should suffice. —Preceding unsigned comment added by 98.199.120.129 (talk) 15:55, 16 October 2007 (UTC)

Changes of Zone - Time & Date

There are various mentions of places which have recently changed Time Zone - I've spotted Chihuahua, Venezuela, Georgia, Sri Lanka, Nepal, Kyrgyzstan, Taiwan, Peninsular Malaysia, Singapore, Marshall Islands, Phoenix Islands, Line Islands. I suggest that it would be well to have a separate list on this page for those and any other reasonably recent (or future) changes; the details in the main list could be replaced by links to that.

There are a few cases where territories have changed from one side of the Date Line to the other, thereby losing or gaining a day. That's of particular interest, and deserves its own list of all known changes however long ago. Alaska 1867, Marshall Islands, Phoenix Islands, Line Islands, at least.

Having separate lists will make omissions more obvious and more likely to be corrected.

82.163.24.100 17:48, 4 November 2007 (UTC)

Missing common time zone names

Is there some reason why an English Wikipedia article titled List of time zones is missing the most common English names and abbreviations of the time zones? I was disappointed that I could not find these here, one of the very rare situations where Wikipedia did not contain some meaningful (i.e., non-trivial), widely-known information that one should expect to find. I realize that, for accuracy and global relevance, we should lead with internationally recognized designations, but it seems absurd not to include the more commonly-known data alongside the official stuff, even where it is ambiguous. (In fact, it's the very ambiguity and other issues, along with explanations, that would make their inclusion here a very useful thing.)

As with so many other articles, I have neither the time nor the expertise to write all this up myself just now, so I ask those who regularly maintain this article if they would consider adding this data (along with cited sources, of course). Thank you. ~ Jeff Q (talk) 06:45, 10 July 2008 (UTC)

To aid this process (and as a reminder in case I have to do it when I get time), here's an apparently reliable source that includes this information:

• ""Time zone abbreviations"". timeanddate.com. Time and Date AS. undated. Retrieved 2008-07-10. {{cite web}}: Check date values in: |date= (help)

Of course, I'm sure there are government sites in several predominately English-speaking countries that would feel even more reliable or official, but this happens to be the current top Google entry for looking up "time zone [abbreviation]". (That's not why I call it "reliable", though. The website itself appears to have at least a 13-year history, is currently ranked 1,176 by Alexa, gets 513,000 Google hits, and is referenced in 178 books collected in Google Book Search.) ~ Jeff Q (talk) 06:58, 10 July 2008 (UTC)

Are there two full hours of three-dates-coexisting?

The article says, "This gives the interesting feature that during one hour each day there are three different dates in use on land around the world." This statement is certainly correct, but I think it doesn't clearly and fully convey how screwed up time zones are. For one thing, I think the "on land" qualifier may be unfairly ignoring "UTC-12: Ships at sea within 7.5° east of 180° and United States Minor Outlying Islands." If we count those people, then aren't there three dates coexisting for a full two hours each day? Another implication of this which isn't clearly mentioned is that there are always at least two dates in use on the surface of the Earth, and there are always at least three time zones using a different date than the majority of world.

Also of note, if we simply didn't have the time zones UTC+12, +13, and +14, then we could still accurately represent the time of day in all parts of the world, but there would never be three dates simultaneously coexisting, and for one full hour each day the entire planet would share a single date.Fluoborate (talk) 19:04, 23 October 2008 (UTC)

Articles on time zones and time offsets

I'm not sure if this is the right place to get attention for this, but it's a start: I came upon UTC+1 via Special:Randompage earlier, and noticed that it didn't actually say what "UTC+1" means.

I went to fix it, but then realised I'd have to fix over 24 other articles; except they're not all the same. And then I realised that there are articles for each time zone (e.g. Central European Time) as well as each time offset (e.g. UTC+1). And then I found this list, which actually has the information fairly well organised.

So:

1. What information should be in pages on named time zones (e.g. Central European Time)? Political, cultural, and historical spring to mind.
2. What information should be in pages on time offsets; as far as I can see, these will only ever be the lists of time zones in that offset. In which case,
3. Do we need both this list and a separate article for each offset?

And am I even making that distinction correctly, since none of the pages seem to... - IMSoP (talk) 01:46, 26 October 2008 (UTC)

[Hm, talking to myself...] To go into a bit more depth, I can see the following information being useful:

For each time offset:

• the offset from UTC (with explanation/link for that convention)
• the geographical boundaries which that offset would theoretically cover if time zones were divided up entirely based on longitude

For each named time zone:

• the name of that time zone (e.g. Central European Time)
• the offset of that time zone from UTC
• the daylight savings rules applied in that time zone, with either a separate article (e.g. Central European Summer Time) or mention of the offsets used in both parts of the year
• the countries / states / localities using that timezone
  • historical information (e.g. countries joining or leaving a timezone)
  • geographical information (e.g. localities outside the theoretical range of that offset using the timezone for practical or political reasons)

Obviously, there's a lot of overlap there, so I'm not sure quite how the articles can be neatly divided (does the fact that much of Spain is actually west of Greenwich but uses UTC+1 belong under UTC+1 or Central European Time, or both?) - IMSoP (talk) 18:44, 26 October 2008 (UTC)

New Discussion

A discussion has been started at Wikipedia talk:WikiProject Countries/Lists of countries which could affect the inclusion criteria and title of this and other lists of countries. Editors are invited to participate. Pfainuk talk 12:07, 17 December 2008 (UTC)

Dagger symbol

Some of the time zone names have a dagger symbol or a double-crossed line indicator. There is no explanation of this, though the double-cross seems to be applied to zones with a difference that includes 15 or 45 minutes. The dagger symbol seems to be used for full-hour different zones 13+ and 14+ and for zones that include a 30 minute difference.

The 13+ and 14+ zones are also indicated M(ike). For my own reference chart, I have indicated they don't have a mnemonic name, but what would NATO call them if they sailed into Tongan or Kiribatian waters? Mike-Plus-One and Mike-Plus-Two? (Yankee and Mike are the same, except Mike is 24 hours ahead of Yankee.) Or Xray-plus-a-day and Whiskey-plus-a-day? I'd suggest "nu" and "omicron" as the Greek equivalents of the next two English letters. GBC (talk) 05:47, 21 February 2009 (UTC)

Also, would it be prudent to indicate Israel and Islamic countries on the chart that may begin the legal date at 6 pm or sunset rather than midnight? I'd suggest a symbol for 6 pm and a symbol for sunset. GBC (talk) 06:01, 21 February 2009 (UTC)

An explanation of the dagger † and double dagger ‡ symbols used to be in the time zone article when this article (list of time zones) was a part of it, but the explanation has now been moved to nautical time. It should be in the lead of this article, suitably modified. Here is the orginal version:

These nautical letters have been added to some time zone maps, like the map of Standard Time Zones by Her Majesty's Nautical Almanac Office (NAO), which extended the letters by adding an asterisk (*) or dagger (†) for areas that do not use a nautical time zone, and a double dagger (‡) for areas that do not have a legal standard time (Greenland's ice sheet and all of Antarctica. The United Kingdom specifies UTC−3 for the Antarctic Peninsula, but no other country recognizes that). They conveniently ignore any zone that does not have an hour or half-hour offset, so a double dagger (‡) has been co-opted for these zones in the list of time zones.

An asterisk * could not be used for half-hour zones because it had already been used in the earliest Wikipedia list for northern daylight saving time (which has been extended to a double asterisk ** for southern DST). The NAO map uses M* and M† for the UTC+13 and UTC+14 zones, respectively, so the usage of M† and M‡ here is only a slight modification. Using nu ν and omicron ο would be too great a change. Also note that the NAO map uses the opposite polarity, that is, it regards zone time as the basis to which an offset must be added to obtain Universal Time. Other time zone maps, including Wikipedia, use Universal Time as the basis, to which an offset is added to obtain the time in other zones.

Time zone maps before about 1970 indicated that the Arabian peninsula did not use a standard time zone by showing it as a blank area (white or black). Indeed, Saudi Arabia did not use standard time at that time, instead it used the local sunset-to-sunset time of each location for prayer times, with specially modified clocks to display it. But during the 1970s Saudi Arabia adopted a standard time zone (UTC+3) and began to publish official prayer times in the local newspaper for each location. These times use the secular 24 hour midnight-to-midnight clock, not any sunset-to-sunset clock. Modern discussions of the Muslim day by Muslim authors (and of the Jewish day by Jewish authors) are always given in terms of the Western midnight-to-midnight day, so they sometimes confuse the two. Given this usage by Muslim (and Jewish) authors themselves, I don't think we should even mention any 6 pm or sunset religious day in this list of time zones. — Joe Kress (talk) 01:56, 22 February 2009 (UTC)

For the purposes of this article there seems to be no need to follow the additional symbols used on the World Time Zone Map. I have used † throughout and added an explanation to the introduction of the article. Coroboy (talk) 19:11, 28 September 2010 (UTC)

Potentially useful link

Someone posted Legal Time 2010 (as of 15 April) at List of country calling codes; while the list is from the ITU, it is just a list of time zones for various countries/regions and has nothing to contribute to that list. But it may be useful as a source here. Anomie⚔ 03:44, 3 May 2010 (UTC)

Not a list of time zones

This is a list of geographic areas by UTC offset. TZ master (talk) 12:39, 7 October 2011 (UTC)

Does this explain why the listing for Newfoundland and the tip of Labrador is off? They are listed as UTC - 4:00 here, but are actually in the Newfoundland Time Zone, which is UTC -3:30 during Standard Time, and UTC -2:30 during Daylight Time. (Source: http://www.timetemperature.com/tzca/newfoundland_time_zone.shtml)

HarmonicSphere (talk) 13:14, 28 February 2012 (UTC)

Removal of daylight savings time indicators

Why have the * and ** indicators been removed from virtually all of the regions in the list? This information was present on the English page before, and is still there on other language pages. It is still documented in the page description:

Regions marked with asterisks (* or **) observe daylight saving time: add one hour in summer (* for Northern Hemisphere summer; ** for Southern Hemisphere).

What possible justification is there for removing this useful information? --67.215.46.59 (talk) 18:11, 22 March 2012 (UTC) Sean Sherrard shermat2atisudotedu

Yes, I find it very regrettable, too, that this information has been removed from the article. This used to be the best list of time zones but, sadly, is not any more.

Is there any possibility that the DST info is put back into this list? Martin --94.194.149.238 (talk) 10:38, 31 December 2012 (UTC)

I think the article would be too cluttered if all the DST information was included. Perhaps an article like List of countries using Daylight Saving Time would be useful to cover the topic? Eldumpo (talk) 21:52, 29 January 2013 (UTC)

The article would not be cluttered by the presence of * and ** because only those symbols were present in the original article — no other information was or will be provided, such as which days of the year DST begins and ends. For that info see Daylight saving time by country. — Joe Kress (talk) 23:44, 29 January 2013 (UTC)

It appears that some contributors feel that year round time is the norm, and the places that use daylight savings time (primarily wealthy Europe, North American countries, and Australia - along with their economically dependent neighbors) are out of step. But we should not be imposing our values on our readers. Rather, we should be describing what is already in place and how it works.

I've been trying to preserve and emphasize the distinction between time zone and time offset, among other things. And I hope to straighten out the daylight saving time mess as well. Anyone want to join in?

Which cities

Not seeing any particular method or pattern to which cities were chosen (other than being capitals), I added the capital (or commercial capitals) of countries that were not represented. Now, another user has come along and deleted at least some of those, leaving the selection particularly short of African cities. What should be the criteria for the list? How about country capital or commercial capital and population more than x (to be determined)? —[AlanM1 (talk)]— 09:24, 8 July 2012 (UTC)

My view is that the principal cities section should be a relatively short list outlining the largest few cities in each offset, with ideally only one city per country. It should not be listing every capital city within the zone. Eldumpo (talk) 13:05, 8 July 2012 (UTC)

I've added some text to the article providing some steer on the inclusion of principal cities, concentrating on not having too many. There's no need for the article to have a long list of cities; these can mostly be easily deduced from the country/region. Eldumpo (talk) 08:22, 21 October 2012 (UTC)

Time zones and time offsets

This article suffers from a confusing perspective. It lists time offsets, as if these were the same as time zones. I know that some websites take the same perspective, but I think this confuses the reader.

A time offset is not the same as a time zone. The UTC time offset observed in a place is the amount of time subtracted from (or added to) Greenwich Time (aka UTC). Many localities in the English-speaking world also observe a daylight saving time by adding one hour from this offset. So they really have two time offsets.

I'm not really sure if it's so good to have a list of UTC time offsets in addition to a list of time zones. Just having the time zone list would probably be a whole lot more clear for our readers. --Uncle Ed (talk) 21:31, 14 July 2012 (UTC)

I think it's really useful to have a list of ordered time offsets, so readers can see at a glance what is in each zone. I agree there could be some confusion between time zones/offsets; the article was named differently until quite recently. I've added a note that this list deals with 'standard' time zones. The time zones list you pointed to was a dab page. Eldumpo (talk) 21:47, 23 July 2012 (UTC)

Problems with the ″time zone number″ notation on the Standard Time Zones Map

The main problem occurs with western longitudes. Next to the top and the bottom edges of the map, the map gives UTC offsets (e.g. -5 for the time zone containing New York). But in the body of the map, one finds something that in the legend of the map is called the ″time zone number,″ and for the time zone containing New York, that number is 5 (i.e. +5). In the legend at the bottom, it says (for western longitudes), ″Add time zone number to local time to obtain UTC. Subtract time zone number from UTC to obtain local time." Now that's correct if one really uses the time zone number, i.e. the number indicated in the body of the map. The confusing part is that right above the legend, what one sees is not the time zone number, but rather the UTC offset, and, of course, if (for the time zones in the western hemisphere) one uses the UTC offset with the prescription given in the legend, one gets a wrong result. (There is no corresponding problem for time zones in the eastern hemisphere, because for them, their ″time zone numbers″ coincide with their UTC offsets.)

The second problem with ″time zone numbers″ is that they are not a unique identifiers for time zones: for every time zone in the western hemisphere with a given ″time zone number,″ there is a time zone in the eastern hemisphere with the same ″time zone number″ (e.g. the time zone containing New York in the U.S. and the time zone containing Karachi in Pakistan both have the same ″time zone number,″ namely 5).

The third problem is that with this system of ″time zone numbers,″ if one wants to convert from local time to UTC or vice versa, then one needs to use different formulas depending on whether one is interested in the time zones in the western hemisphere or in the eastern hemisphere. This is evident from the legend. In contrast, one and the same formula using UTC offsets is valid for time zones in both hemispheres: ″UTC″ = ″local time in a zone″ - ″UTC offset for that zone″. The only problem with that (if it is a problem at all) is that one needs to know how to do arithmetic with negative numbers (e.g., in the winter, the UTC offset for New York's time zone is -5, so when it's 15:47:00 in New York in the winter, the UTC time is computed as 15:47:23 - (-5:00) = 20:47:23 UTC). In the system used in the map, one only ever does arithmetic with positive numbers.

The fourth problem is that it is unclear what reputable source uses this kind of ″time zone numbers.″ This map, and some similar to it, can be found at the University of Texas at Austin library online map collection, here. Indeed, the map under discussion seems to be precisely this map. Note, however, that in maps from 2005 and earlier, the numbers shown next to the top and the bottom edges of the map are not the UTC offsets but rather the ″time zone numbers,″ so the main problem discussed above does not occur. However, the remaining problems are still there. In particular, it is not clear who or what produced these maps. On the other hand, reputable sources I was able to find do not use this system of ″time zone numbers.″ One reputable source, the 2002 edition of Bowditch's American Practical Navigator, uses positive numbers for the western hemisphere, and then continues with negative numbers in the eastern hemisphere (e.g. New York's time zone is labeled ″5″, while Karachi's is labeled ″-5″). To see this, download Chapter 18 (″Time″) here, and look at the map in Fig. 1806 on p. 279. This is consistent with the U.S. Navy manual available here. Other systems (arguably) use the UTC offsets as designators for time zones, e.g. here and here. Still other systems do not use number designators at all. For example, this map, on which it says that it was ″Compiled by HM Nautical Almanac Office,″ uses only letter designators.

How best to resolve these problems would seem to depend on how one resolves the confusion between the concepts of ″UTC time offset″ and ″time zone,″ and between the concepts of ″standard time″ and "standard time zone"; this confusion is discussed here. However, as a temporary resolution, one could simply follow what seems to be the natural instinct and use the UTC offsets as time zone numbers. This would require two rather easy modifications of the map: 1. adding the minus signs in front of the ″time zone numbers″ in the body of the map in the western hemisphere, and 2. appropriately changing the conversion recipe in the legend. Reuqr (talk) 10:28, 25 September 2012 (UTC)

The map in this article is derived from the map entitled Standard Time Zones of the World published periodically by the Central Intelligence Agency [1] (row 5, col 3, 10-12). As you note, the University of Texas library has several versions online. The latest versions have negative time zone numbers along the top and bottom edges of the Western hemisphere, but not within the countries themselves. The left-hand note is wrong when applied to the edge numbers, but correct when applied to the country numbers of the Western hemisphere. To avoid confusion, all country numbers in the Western hemisphere should have minus signs to match the numbers on the top and botton edges, and the left-hand note should be removed, leaving only the correct right-hand note. — Joe Kress (talk) 23:37, 5 February 2013 (UTC)

Misleading presentation

This system where a following right indent "cancels" the previous line seems highly counter-intuitive and misleading. Any better suggestions? I though perhaps replace

• Russia
  • ...

with

• In Russia:
  • ...

There also ought to be information about summer time use (as it seems from discussion on this page that there once was). W. P. Uzer (talk) 07:58, 2 August 2014 (UTC)

I think the indent is generally OK, maybe the blue note under the map could be clarified, but I don't see the need to add 'In' to every line.

Adding daytime/summer times would make the article quite messy and too long. Maybe instead create List of daylight saving UTC time offsets, and create appropriate links between the two articles? Eldumpo (talk) 08:02, 3 August 2014 (UTC)

The blue note under the map is quite OK, but not everyone will notice it and digest it before they start looking at the article - there shouldn't be a need for such a note, as the information should be presented in an intuitive way to start with (e.g. by adding "In" to the lines in question - I don't mean to every line, just the ones which imply something that isn't true, like Russia when we don't mean the whole of Russia). I also don't quite understand your suggestion about summer times - can you explain in more detail how that would work? W. P. Uzer (talk) 22:55, 3 August 2014 (UTC)

I'm not convinced there is an intuition problem with the indents but try changing one of them to see how it looks. Re summer times, I was suggesting there could be a separate page listing all those countries where there is daylight saving, and what it is (suitably sourced of course). Eldumpo (talk) 06:18, 4 August 2014 (UTC)

I started off repairing the presentation; I'll do the rest of the zones if no-one objects. Admittedly "In..." doesn't really work when we're referring to possessions rather than integral parts of the country, but different wording can be used when appropriate. W. P. Uzer (talk) 10:00, 4 August 2014 (UTC)

I don't think it looks better. It seems to be adding words for the sake of it. Why say 'Territory of France'? Eldumpo (talk) 19:49, 5 August 2014 (UTC)

I agree it doesn't look better, but the way it's been up to now is just plain misleading. There are no doubt still better ways to do it, but if you simply list "France" without any qualification, then people are going to assume (admittedly less likely in that case than in some of the others) that "France" is included in the things you are listing. Even knowing the system, I find myself misled as to what's being said (especially when there are two levels of indentation). Maybe better to just list the territories without mentioning which countries they belong to (or putting their status in parentheses after their names, as is quite usual), and reserving indentations for the cases of countries that are divided into time zones, like the U.S. and Russia. W. P. Uzer (talk) 20:35, 5 August 2014 (UTC)

Given the way the list is presented I can't see why people wouldn't think each entry only includes the right-most bullet, but noting they may not see the blue note. The list though should continue to show the ultimate sovereign country e.g. not just jump straight to 'French Polynesia'. Ideally could do with some more views on this. Eldumpo (talk) 06:36, 6 August 2014 (UTC)

I left a message at Wikipedia talk:WikiProject Lists, asking for views. For anyone coming into this discussion, a sample of the kind of changes I think are necessary is shown in this diff (for discussion purposes, I've self-reverted the changes for now). W. P. Uzer (talk) 07:34, 6 August 2014 (UTC)

Tabulating ideas

It's confusing. I recommended tabulating the list. I'd recommend the columns go something like 1) Time offset, 2) Specific place experiencing it, 3) where place is in the world (country, state/province), 4) reference. You should be able to remove the note altogether than. But i will leave it up editors more failure with this topic to hash it out, I'm just a list expert. Dkriegls (talk to me!) 11:26, 6 August 2014 (UTC)

OK, I note someone else has found the current format confusing. Maybe a list could work but if the columns were done as above then for each offset all the places under the same country should be listed consecutively, but will some entries need another column to sufficiently detail matters. Maybe a 5th column for notes/comments. Also, what happens for sovereign countries in 1 time zone - the 2nd column would be blank or duplicate the 3rd? Maybe someone could do a trial list format to see how things look? Eldumpo (talk) 06:19, 7 August 2014 (UTC)

Personally I don't think a table would work so well; it would be more fussy and awkward to read (for what is, for a large part, essentially just a simple list of countries) and would take away the flexibility that the indentation system gives us. My main objection is just that, when the indentation system is used, those lines whose scope is going to be restricted by subsequent lines ought to be worded in some way that makes clear that this is the case; it isn't natural for the human eye/brain to interpret a line differently purely on the basis that it's followed by a further indented line. Just adding a colon to those lines would be of some help, though for better clarity I think there should also be additional wording like "In..." Also, it doesn't seem natural to list everything under "ultimate sovereign country", when it's a distinct territory rather than just a designated time zone integrally within the country. W. P. Uzer (talk) 06:03, 8 August 2014 (UTC)

Missing Areas

Where is Connecticut on this list? Thanks. Joseph A. Spadaro (talk) 16:00, 22 September 2014 (UTC)

Westernmost Mongolia seems to be unaccounted for (only the zone named after Ulaanbataar (most but not all of the country)) is included. 2601:204:D502:1837:69EB:4883:1215:3DFE (talk) 15:53, 31 December 2017 (UTC)

Possible vandalism

These edits are by a suspected vandalism-only account. But the addition of Malé looks OK to me so I've corrected it. Feel free to revert my edit if I have it wrong, and of course the others if in fact they are also wrong. Or even revert my edit if it just makes it easier to fix the damage, it's easily redone. TIA Andrewa (talk) 07:08, 10 October 2018 (UTC)

A Commons file used on this page has been nominated for deletion

The following Wikimedia Commons file used on this page has been nominated for deletion:

• Standard World Time Zones.png

Participate in the deletion discussion at the nomination page. —Community Tech bot (talk) 16:08, 25 November 2018 (UTC)

Adding and re-ordering cities

@Lachlb: you have several times added a bunch of cities, and moved away from alphabetical order in the lists, without so much as an edit summary to say why. You have been reverted thrice now. Please take this opportunity to say why you think this improves the article, or refrain. Dicklyon (talk) 16:08, 2 March 2019 (UTC)

@Lachlb: Thank you for belatedly adding summaries to your edits although you seem to have re-added all of the items that were subject of the reversions. Please note that the long-standing consensus is that each time zone should have a maximum of one city per country, not all countries need to have a city listed and not all time zones need to have cities listed; it is supposed to be a high-level overview of the largest cities. I have made a number of changes to the article, including returning time zone entries that reflect sources. Please do not continue to re-add disputed information without discussion. Thanks. @Dicklyon: Eldumpo (talk) 17:48, 6 March 2019 (UTC)

@Lachlb: – changes came back yesterday, with no discussion that I can see, so I reverted them again today. Dicklyon (talk) 01:22, 12 March 2019 (UTC)

I made the sections below into subsections, as they address this topic. Dicklyon (talk) 01:23, 17 March 2019 (UTC)

Why there should sometimes be two principal cities

I think there should be sometimes two principal cities in in a few time zones like UTC+10:00, UTC+08:00, UTC+05:30, UTC-07:00 and UTC-09:00 because China in UTC+08:00 has Shanghai as its largest city and Beijing as its capital, India in UTC+05:30 has Delhi as its largest state and Kolkata is the 6th largest city, Phoenix is the largest city in UTC-07:00 but does not use daylight saving time but Denver is the second largest city in the U.S.A in this time zone and uses daylight saving time and Alaska in UTC-09:00 has Anchorage as its largest city and Juneau as its capital city. Lachlb (talk) 09:32, 15 March 2019 (UTC)

It’s supposed to be just a quick overview of key cities, not a large number. We don’t need to show both capital and biggest city. I’m not convinced it’s needed at all, maybe best it should follow a source. Eldumpo (talk) 21:37, 16 March 2019 (UTC)

São Tomé and Principe time zone

São Tomé and Principe has changed its local time back again to Greenwich Mean Time. Lachlb (talk) 09:33, 15 March 2019 (UTC)

Thanks for engaging at talk. Please can you add a citation for this and the Kazakhstan claim. Eldumpo (talk) 21:41, 16 March 2019 (UTC)

Kyzylorda, Kazakhstan time zone

Kyzylorda in Kazakhstan changed time zone from UTC+06:00 to UTC+05:00 Lachlb (talk) 09:34, 15 March 2019 (UTC)

Why there should be principal cities in UTC+13:00, UTC-01:00, UTC-03:30 and UTC-11:00

I think there should be two principal cities in UTC+13:00 because Apia, Samoa is the largest city in this time zone and Nuku’alofa, Tonga is the second largest city in this time zone. I think there should be two principal cities in UTC-01:00 because Praia, Cabo Verde is the largest city in this time zone and Ponta Delgada Portugal is the second largest city in this time zone. I think there should be one principal city in UTC-03:30 because St. John’s, Newfoundland and Labrador, Canada is the largest city in this time zone. I think there should be one principal city in UTC-11:00 because Pago Pago, American Samoa is the largest city in this time zone Lachlb (talk) 09:47, 15 March 2019 (UTC)

UTC+05:30 principal cities

I think Mumbai and Kolkata should be principal cities in UTC+05:30 because Mumbai is the largest city in India and Kolkata is the sixth largest city in India and I don’t think Delhi should be a principal city because it’s too small. Lachlb (talk) 09:51, 15 March 2019 (UTC)

Seriously, Delhi is small? Is there not some other criterion for "principal" other than size? Dicklyon (talk) 01:21, 17 March 2019 (UTC)

UTC-04:00 principal cities

I think Cuiabá and Asunción should be principal cities in UTC-04:00 because they use daylight saving time. Lachlb (talk) 10:15, 16 March 2019 (UTC)

I don’t see why daylight saving is an issue; the list is not showing daylight saving but standard time. Eldumpo (talk) 23:32, 16 March 2019 (UTC)

While Daylight Saving Time does place these cities at UTC-04:00, I think it would be better to choose as principal cities those that are in UTC-04:00 due to Daylight Saving Time. Are there significant deviations from this idea already? Dicklyon (talk) 01:26, 17 March 2019 (UTC)

I’m unsure if there is a 'not' missing from your post. However, there is a note in the article saying that countries should be listed according to their standard zone not DST, and we could explicitly say this applies to the cities that are listed as well. Eldumpo (talk) 23:39, 19 March 2019 (UTC)

Sorry, I meant "those that are in UTC-04:00 due to Standard Time". I agree with you. Dicklyon (talk) 03:33, 20 March 2019 (UTC)

UTC-03:00 and UTC+01:00 principal cities

I think Nuuk should be a principal city in UTC-03:00 because it uses daylight saving time and I also think Luanda, Algiers and Vienna should be principal cities in UTC+01:00 because Luanda and Algiers have over 3 million people and Vienna is the world’s most liverable city Lachlb (talk) 10:19, 16 March 2019 (UTC)

Nuuk is tiny and as per the notes not all countries/time zones need have a city listed. Eldumpo (talk) 23:40, 19 March 2019 (UTC)

Why there should sometimes be two or more principal cities

I think there should sometimes be two or more principal cities because my argument is only being one city per country is because it doesn’t match other time zone related articles, so I believe there should be two or more cities because my argument is it improves the article more by matching more related time zone articles. Lachlb (talk) 22:57, 15 June 2019 (UTC)

Following those individual time zone articles shouldn’t be the basis for what this article does, maybe instead they should change? Perhaps we should consider using tz or World Time Zone although this should be agreed before changes are made. Eldumpo (talk) 14:28, 16 June 2019 (UTC)

Recent efforts to improve coverage of principal cities, etc.

Hi Dicklyon and Eldumpo, I live in Melbourne, Victoria, Australia, I have studied Time all around the world and I was trying to help fix the Wikipedia up for you because I found out the Turks and Caicos Islands reintroduced Daylight saving time by setting the clocks back 1 hour to Eastern Standard time on November 4, 2018, Kyzylorda changed time zone to from UTC+06:00 to UTC+05:00 on 21, December 2018 and São Tomé and Principe changed its time zone back to UTC+00:00 on January 1, 2019, I found out all of this information on the timeanddate app. I have also found out that Calgary is the largest city in Alberta and has got more people than Edmonton that is why I have put Calgary as principal city in UTC-07:00 instead of Edmonton, Mumbai is the largest city in India and Delhi is just a state that is why I have put Mumbai as a principal city in UTC+05:30 instead of Delhi, Shanghai is the largest city in China and has got more people than Beijing that is why I have put Shanghai as a principal city in UTC+08:00 instead of Beijing, I have added Macau as a country in UTC+08:00 because it’s also a country in UTC+08:00 and I have found out that the real time zone in Russia in UTC+11:00 is Magadan Time, that is why I have put Magadan Time instead of Srednekolymsk Time. I have also added Managua, San Salvador and Tegucigalpa to UTC-06:00 in order to match the article UTC-06:00. I have also added Asunción as a principal city to UTC-04:00 in order to match the article UTC-04:00, and I have also added Algiers, Luanda and Vienna as principal cities to UTC+01:00 in order to also match the article UTC+01:00. I have also sorted out the principal cities in UTC+01:00 and UTC+00:00 from European cities first as principal cities from largest to smallest by population then African cities from largest to smallest by population. I have also sorted out UTC-05:00 principal cities from American cities first from largest to smallest by population then Caribbean cities from largest to smallest by population and then I’ve sorted out South American principal cities from largest to smallest by population. Thank you for your letters about my proposed changes to this article. Lachlb (talk) 10:48, 6 May 2019 (UTC)

Lachlb, that's great that you're trying to improve the article. You've probably noticed that other editors also care about the time-zone articles, and don't always agree with your changes. That's why you need to be more involved in discussion when disagreements arise; otherwise your work will be mostly reverted and we won't here what the thinking was behind your edits. If you could comment on the feedback you've gotten, other editors will be in a better position to comment, possibly breaking a tie. Thanks for engaging here. Dicklyon (talk) 02:06, 12 May 2019 (UTC)

There is an offical source on time zones and principal cities. It is called tz database. This source is used by several opeating systems like Android and Unix. This database is listed in List of tz database time zones. For Mountain time in Canada it is Edmonton, the state capital. This way we can use a source to what is principal cities in the time zones (usually one per country and for countries with multiple time zones or historically after 1970 multiple time zones, one per time zone in the country). And don't have to argue on personal opinions or personal criteria. And Lachlb, don't edit that list, because it is based on an external database.--BIL (talk) 09:22, 12 May 2019 (UTC)

Hi BIL and Dicklyon thank you for your letters about my changes to this article. I have made a number of changes to this article and these changes were in UTC+02:00 I replaced Kaliningrad with Lubumbashi and moved Athens between Johannesburg and Kiev and I did this in order to match the article UTC+02:00 and to sort out European cities smallest to largest. I have also added principal cities to UTC-03:30 and UTC-01:00 in order to match the articles UTC-03:30 and UTC-01:00 I have also added two cities per country in UTC-07:00, UTC+05:30, UTC+08:00, UTC+09:30 and UTC+10:00 in order to match the articles UTC-07:00, UTC+05:30, UTC+08:00, UTC+09:30 and UTC+10:00. I have also found out that the Magallanes Region of Chile uses daylight saving time year round that is why I have put this region in Chile in UTC-03:00. I have made all these changes to this article because I want to improve the article more by matching other articles and fixing things that are not correct. Lachlb (talk) 07:25, 17 May 2019 (UTC)

@Lachlb: You comments didn't really respond to BIL's note. Please say whether your changes are in line with the official source he showed, and if not why not. Dicklyon (talk) 16:01, 18 May 2019 (UTC)

Hi Dicklyon, the reason I also mentioned BIL because I wanted to thank the user for his letter about the topic.

I have also corrected time in Ecuador that the only part of the country that is in UTC-06:00 is the Galápagos Islands that is why I have written except Galápagos Islands in front of Ecuador in UTC-05:00. I have also added Abidjan as a principal city in UTC+00:00 in order to match the article UTC+00:00 and I have also added Tbilisi and Yerevan as principal cities in UTC+04:00 in order to match the article UTC+04:00, I have also added Edmonton and Hermosillo as principal cities in UTC-07:00 in order to match the article UTC-07:00, I have also added Brisbane as a principal city in UTC+10:00 in order to match the article UTC+10:00, I have also removed Praia and Ponta Delgada in UTC-01:00 because the population is under 1 million and I have also removed Papeete in UTC-10:00 because the population is only 26,926. Lachlb (talk) 23:05, 15 June 2019

Chile time zones

Not all of mainland Chile is in UTC-04:00 because the Magallanes Region is on UTC-03:00 year round since 2016 according to various time zone apps. I have also added a reference supporting my changes to the time zones. Lachlb (talk) 07:32, 16 June 2019 (UTC)

You didn’t add a reference, but in any case this article is only showing the standard (non-DST) position. Eldumpo (talk) 14:25, 16 June 2019 (UTC)

I see that the change is not just DST so I have changed it back with a reference. Please add citations directly within the text. Eldumpo (talk) 08:01, 17 June 2019 (UTC)

South Africa time zones

I just corrected South Africa time zone by saying expect Prince Edward Islands in front of it in UTC+02:00. Lachlb (talk) 04:43, 22 June 2019 (UTC)

I just sorted out the states of country’s in alphabetical order

I have just sorted some countries provinces and states in alphabetical order. Lachlb (talk) 04:43, 22 June 2019 (UTC)

Why I have put Calgary as a principal city in UTC-07:00 instead of Edmonton

The reason why I have put Calgary as a principal city in UTC-07:00 instead of Edmonton because Calgary has more than 1 million people and Edmonton doesn’t. Lachlb (talk) 05:40, 22 June 2019 (UTC)

Incorrect time zone for Crimea

It's part of Ukraine, not Russia, so it has to use Ukrainian time zone. — Preceding unsigned comment added by 2A01:E35:1392:1090:D8C8:F473:CB75:B35B (talk) 22:29, 18 August 2019 (UTC)

Just because one geographic subdivision is "part of" another doesn't mean they have to share the same time zone. Can you cite a source that verifies what you are claiming? - dcljr (talk) 04:21, 19 August 2019 (UTC)

There is only one timezone in Ukraine, https://www.timeanddate.com/time/zone/ukraine / http://ua.korrespondent.net/ukraine/events/1273613-rishennya-radi-ukrayina-30-zhovtnya-perejde-na-zimovij-chas. Crimea is a part of Ukraine, https://en.m.wikipedia.org/wiki/United_Nations_General_Assembly_Resolution_68/262.

— Preceding unsigned comment added by 2a01:e35:1392:1090:d8c8:f473:cb75:b35b (talk • contribs) 20:24, 19 August 2019 (UTC)

(Please sign your talk page posts.) OK, well, timeanddate.com, your first source, actually explcitly indicates that Sevastopol, Ukraine (in Crimea) is set to the same time as Moscow, Russia. (Note that a news item from October 24, 2014 at the same website, which is already cited in the article, states: "Crimea already moved its clocks to Moscow Time as Russia annexed the peninsula in March 2014.") Your second source is from 2011, so what it says is no longer relevant (whether or not what it says is in fact still true, it certainly can no longer be assumed to be true, since obviously the situation might have changed since 2011). As for the UN resolution, unless it specifically talks about what time zone Crimea is using (which seems very unlikely), its relevance for this discussion is at best questionable. But I will leave it for others more knowledgable about world time zones to carry this discussion any further. - dcljr (talk) 01:42, 20 August 2019 (UTC)

No, Crimea is part of Russia after 95.5% of 86% of all Crimea people voted to be apart of Ukraine and part of Russia; what is more important is that even before our annexation by force of Crimea there was UTC+02:00 (with DST, but DST should have occured on 30 March (3rd sunday of March) in 2014) time in Crimea, a while after annexation on 30 March it instead became UTC+04:00 (because our ex-president Medvedev introduced UTC+04:00 permanent DST, that broke many programs that calculated time as it technically introduced new timezones), but 6 month after annexation Moscow reversed it and Crimea now have permenent non-DST as well as Moscow. Ukraine still have UTC+02:00 with DST, so in summer our time is the same. 2A00:1FA0:212:E031:2974:D883:ED3F:4F4C (talk) 14:38, 17 June 2020 (UTC)

Clutter from IP

An editor using at least 2 different IP addresses has been cluttering the list up with flags and with countless minor locations. These edits do not seem to be an improvement. --David Biddulph (talk) 07:29, 18 August 2021 (UTC)

I agree these were not an improvement. Good reversion. Eldumpo (talk) 07:47, 19 August 2021 (UTC)

More IP addresses, doubtless socks of the already blocked IPs, are swamping the pages for each time zone with a ludicrous number of examples of locations. Is there a consensus for these changes? --David Biddulph (talk) 11:15, 31 August 2021 (UTC)