Talk:Military time zone

Timezone Versus Offset Designation

"This is a list of time zone names" should likely be changed to something more like "This is a list of military designations for given UTC offsets". For example, the Canadian Forces treat Romeo and Quebec as offset designations (-0500 and -0400 respectively), and use the local time zone (Eastern) when referencing a timezone.

Thoughts? Perhaps this would also suggest a change of title. —Preceding unsigned comment added by Guidedbycthulhu (talk • contribs) 17:43, 10 August 2010 (UTC)

The designation was decided by the International Telecommunications Union (ITU) in the mid- 1950's and they designated the letters to each time zone. The designation was taken up by the military forces of NATO by 1959 and since by other military forces through the world. It is also used now by the mercantile fleets of most countries. The fact that the US Military uses it does not in anyway confer originality on the US - much as they might like to claim it. The conference was held in Switzerland by the International Telecommunications Union.The Geologist (talk) 15:43, 18 January 2013 (UTC)

How about List of NATO time offsets? The lede could then point out what Geologist says about its adoption by (1) other military forces and (2) mercantile fleets. --Uncle Ed (talk) 15:05, 22 November 2013 (UTC)

I agree. Timezone usually means a volatile set of rules that depend on some government. To my understanding, this is just a list of named offsets that the ACP standard misnamed as time zones, making them look more complicated than they are. 85.187.62.189 (talk) 09:59, 28 April 2022 (UTC)

Juliet Designation

I wasn't able to find anything other than this, and things that referenced it backing the use of J/Juliet. RFC 822 even states (Page 26) “The letter "J" is not used.” Added a tag for now, but if this isn't suppported anywhere, it should be removed. PiAndWhippedCream (talk) 12:59, 5 April 2013 (UTC)

I agree... I have not been able to find a reference that the military would consider authoritative for the use of "J" time zone designator to indicate local. If you know of it, I would be very interested to learn what it is. Thank you, Captpossum (talk) 12:39, 24 March 2015 (UTC)

Also agreed. Changed the text to reflect more of an optional use in some locations/fields; and not to take it as anything official. I also couldn't find any actual references for the usage of the "J" designator (ACP 121 only states that "J" is omitted). Some thing interesting that I did find is that in the Canadian Forces, some individuals/units actually used the "L" time desingator as "Local", which is also incorrect!Tharkhold (talk) 12:49, 26 March 2016 (UTC)

The follow text is a little odd:

some alphabets, including Cyrillic do not have a "J"

Cyrillic doesn't have most Latin letters because its origins are different. Some alphabets have no Latin letters yet only Latin letters are used in this scheme. There seems to be no value to the quoted statement. Danielklein (talk) 04:24, 22 September 2019 (UTC)

Daylight savings time

The text "which does not use daylight savings" should be removed. It implies GMT uses DST, which it does not. This is a common error especially by those that live in the UK area. The time in Greenwich is not synonymous with GMT. Sometimes the time in Greenwich is GMT+1 (British Summer Time BST). — Preceding unsigned comment added by Kaell (talk • contribs) 18:02, 27 May 2013 (UTC)

Yeah, when was Greenwich Mean Time ever offset for daylight saving? I'm going to remove that misleading sentence if there's nothing to it. --Uncle Ed (talk) 15:10, 20 November 2013 (UTC)

Reference

Out of pure curiosity, How do they refer to places where DST applies? For instance, I live in Spain. If I had to refer to 22:00 local time during summer time, would it be any of these?

1. 2100A (our official time, the one we use in the winter, is UTC+1, therefore the time without DST would be 21:00)
2. 2200A (simply ignoring whether DST applies or not, and thus applying the local official time at the given date)
3. 2200B (which would be our summertime in the ALFA zone, UTC+2)
4. 2100A+1 (or something else to make clear it is summer time)

?
Thanks in advance for any clarifying answer!

195.57.19.102 (talk) 09:53, 13 June 2014 (UTC) (sorry about this IP address, it is used for a very large network, and thousands of people use it)

The East Coast of the United States alternates between Q and R time zones to account for daylight saving time. Captpossum (talk) 12:44, 24 March 2015 (UTC)

Is that a standard, to change your time zone code for Summer time? For example, Sydney is Kilo zone and normally UTC+10; does it become Lima zone in Summer when it's UTC+11? Could someone who knows what they are on about please put some information in this article concerning that? Thanks. Mathsgirl (talk) 11:55, 23 May 2016 (UTC)

Dear @195.57.19.102: It would be both "2100A" and "2200B", with the latter one being preferred. Never "2200A", nor "2100A+1". Please refer to pages 3A-1 and 3A-2 of the ACP 121(I). Kind regards, --Usien6 ^{msg • his} 21:51, 26 August 2017 (UTC)

RFC 822

There seems to be a contradiction here. RFC 822 appears to be the opposite to what is listed here. While the "Military Time Conversion & Time Zones Charts" link agrees with what is here.

Is RFC 822 wrong, is the Standard for the Formate of ARPA Internet Text Messages purposly the reverse of military time zones, or is there something I am missing?

References:

54.240.196.186 (talk) 22:00, 5 December 2013 (UTC)

I agree. RFC822 does indeed seem to be the reverse of what is given here. I haven't yet found an official document specifying the system here (and perhaps some of the primary sources are classified documents), but I have removed the confusing reference to the RFC. --David Biddulph (talk) 12:40, 2 October 2014 (UTC)

On further investigation I see that the confusion in RFC822 is pointed out at http://www.hackcraft.net/web/datetime/#note2

RFC 1123 pointed out the error in RFC 822.

The confusing material has been removed from later specifications such as RFC 3339.

Thanks to 54.240.196.186 for pointing out the error. --David Biddulph (talk) 12:59, 2 October 2014 (UTC)

This error in RFC822 is somewhat understandable given the historical context: around the same time as RFC822 was written TZ timezone strings expressed the offset as negative of the customary value, describing it as "hours _behind_ GMT". Martin Kealey (talk) 03:08, 30 March 2021 (UTC)

And it gets worse; the American Practical Navigator in chapter 18 paragraph 6 says:

> Each time zone is identified by the number of times the longitude of its zone meridian is divisible by 15°, positive in west longitude and negative in east longitude. This number and its sign, called the zone description (ZD), is the number of whole hours that are added to or subtracted from the zone time to obtain Greenwich Mean Time (GMT). Martin Kealey (talk) 03:24, 30 March 2021 (UTC)

Mike and Yankee times

Mike and Yankee times seem to be the same time zone. - Ac44ck (talk) 17:34, 22 June 2014 (UTC)

Dear @Ac44ck: Not really. The Mike Time Zone ranges from 172.5° east to 180.0° while the Yankee Time Zone ranges from 180.0° to 172.5° west. Please note these two are unusually short: they measure only 7.5° of longitude, each, while every other zone covers 15°, each. One could say "they were broken into two". Refer to page 3A-1 of the ACP 121(I). Kind regards, --Usien6 ^{msg • his} 22:09, 26 August 2017 (UTC)

UTC Offsets - West / East ~ Negative/Positive ?

Hi,

I'm a total newbie to Wikipedia editing, so please let me know if I'm not following protocol properly.

It seems to me that the paragraph below contradicts the table further down in the article.

  Going east from the prime meridian at Greenwich, letters Alpha through Mike (skipping "J", see below) are used 
  for the 12 time zones with mainly positive UTC offsets until reaching the International Date Line. Going west from 
  Greenwich, letters November through Yankee are used for zones with negative time offsets.

If the table is correct then I think this paragraph should read something like:

  Going west from the prime meridian at Greenwich, letters Alpha through Mike (skipping "J", see below) are used 
  for the 12 time zones with negative UTC offsets until reaching the International Date Line. Going east from 
  Greenwich, letters November through Yankee are used for zones with positive time offsets.

Regards,

dpbaril 11:59, 2 October 2014 (UTC) — Preceding unsigned comment added by Dpbaril (talk • contribs)

Your confusion arose because an IP editor made changes yesterday that got the table back to front. I have now put it back to the correct version. Zone A is the first one to the East of Greenwich, Central European Time, UTC+1, 1300 there when it is 1200 GMT. --David Biddulph (talk) 12:23, 2 October 2014 (UTC)

Star designation for ±0030

I'm on a university network right now; hopefully this post still turns out fine.

I have read that a time zone which is thirty minutes more extreme of UTC than a time zone uses an * (asterisk, pronounced "star") to show it. For example, Indian Standard Time (UTC+05:30) is written E* and pronounced "echo star," indicating that it is thirty minutes farther from UTC than E.

The ACP document we have here uses N* for N with a footnote, so clearly this distinction is not relevant to them-- they do not offer a NATO phonetic for such ±0030 zones.

Any ideas or additional sources? 72.0.129.26 (talk) 16:19, 23 March 2016 (UTC)

Dear @72.0.129.26: Nope. Neither does the section 1806 of the The American Practical Navigator. Kind regards, --Usien6 ^{msg • his} 22:14, 26 August 2017 (UTC)

Unfortunate phrase suggesting non-existence of existing letter

Article states now that " the letter "J" was skipped to avoid confusion with "I" (as was the custom of the time) and because some alphabets don't have one (such as Cyrillic)" which contains suggestion that letter Й doesn't exist, and that's obviously not the case. I'm not sure if there are alphabets that don't have a letter corresponding to "J" but the Cyrillic script is clearly not one of them. Jarosław Komar (talk) 05:32, 21 May 2017 (UTC)

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Remove all of ‘UTC’?

ISO_8601#Time_zone_designators says, backed up by a source, that “the ACP 121 standard that defines the list of military time zones makes no mention of UTC and derives [its time zones] from the Greenwich Mean Time”. So, shouldn't we replace ‘UTC’ with ‘GMT’ in the table? ◅ Sebastian 06:30, 2 June 2023 (UTC)

Well, if you look at the next sentence, that ISO 8601 page says "GMT is no longer precisely defined by the scientific community and can refer to either UTC or UT1 depending on context." On Greenwich Mean Time, it says "English speakers often use GMT as a synonym for Coordinated Universal Time (UTC)", so it is clear that the ACP standard refers to what is now UTC. So it is more precise to use UTC, as GMT is an ambiguous and old term. Mathnerd314159 (talk) 14:35, 2 June 2023 (UTC)

While I agree that ACP 121 would be “more precise” if it used UTC instead of GMT, it is not our task here to correct that standard - that would be WP:OR. Therefore, we need to adjust the article to what the standard actually says. Sorry. ◅ Sebastian 17:09, 2 June 2023 (UTC)

There are plenty of sources that use UTC, e.g. https://veteran.com/military-time/, so it's not OR. The issue is just that the standard is pretty old and the actual training manuals used by the military are classified so there's not a highly reliable source to cite. Mathnerd314159 (talk) 17:41, 2 June 2023 (UTC)

Good - then we can use one of them for my suggestion in the next paragraph. Would you have a good quote for that? ◅ Sebastian 18:12, 2 June 2023 (UTC)

How about if, instead of correcting what the standard says, we added an explanation along the lines of “For all practical purposes, GMT can be understood to mean UTC”. Even for that, we should have a reference. The next sentence from the article, which is referenced, too, unfortunately doesn't directly express that. Would anyone have a better source for that statement? ◅ Sebastian 17:32, 2 June 2023 (UTC)

I added something, seems about as much as can be said on the topic. I get the impression that nobody actually uses the letter zones anymore (besides Zulu), but I haven't found a reliable source for that yet. Mathnerd314159 (talk) 18:39, 2 June 2023 (UTC)

Thanks. Of your recent nine edits, I presume you mean your addition of “The ACP 121 standard actually refers …”. That is a step in the right direction. But now the article basically calls a spade a shovel, only to then explain that it's actually a spade. Yes, I sympathize with your desire to simplify reality, but we have to stick with reality here, not with how we wish it were.

It's also nice that you added more than one source. But it seems they both share the same problems:

• They don't even mention the standard in question. So at the least we can't equate our table as it currently is with “the ACP 121 standard”.
• While both websites look trustworthy to me personally, they are both tertiary source which don't meet the criteria of our guideline. In particular, I don't see any fact-checking or review process. While I understand and sympathize with the problem with classified information you mentioned earlier, at the same time this should make us more circumspect, rather than less. ◅ Sebastian 19:10, 2 June 2023 (UTC)

Well, the ACP standard is a primary source, so it also doesn't have much weight. I mean, I can and did use it for "The ACP standard uses GMT", but to use that to imply that the military prefers GMT to UTC would be a synthetic claim, which is forbidden for primary sources. In this case the secondary source (UTC replaced GMT) contradicts it. According to the policy, WP:TERTIARY, "tertiary sources may help evaluate due weight, especially when primary or secondary sources contradict each other", so since the tertiary sources use UTC that's what the best choice is.

I kind of want to use the tertiary sources to correct ALFA to ALPHA, but I guess that's a separate issue, and actually it seems the mispelling was deliberately introduced in recent years so this is a case where primary and secondary outweigh tertiary. Mathnerd314159 (talk) 21:05, 8 June 2023 (UTC)

Thanks for your reply. I now can better understand where you're coming from. I completely agree that using the primary source to conclude that the military prefers GMT to UTC would be a synthetic claim. I presume that's what you mean by “it also doesn't have much weight”. But therein lies your mistake: The guideline does not say that primary sources in general don't have much weight. Of course it does have weight when we, as we do here, report on that very source. The precaution in the guideline is to prevent inappropriate use, such as “interpretative claims”. It's clearly not an “interpretative claim” to say that the standard uses GMT - that's just an obvious fact. Conversely, it is an “interpretative claim” (and even an absurd one) to conclude from the fact that a tertiary source prefers UTC to GMT that the standard uses UTC. ◅ Sebastian 08:48, 15 June 2023 (UTC)

The question whether to correct ALFA to ALPHA is a separate issue, indeed. What you write about it sounds reasonable, and I have no objection. ◅ Sebastian 08:48, 15 June 2023 (UTC)

November Timezone

Is the table correct?

It seems unlikely to me that November would represent two very different timezones, namely - UTC−01:00 and UTC+13:00. These two are not the same, and they are not a whole day (24 hours) apart. They are 12 hours apart and should be on opposite sides of the world.

If UTC+13:00 does share the same letter as another timezone it should surely be X-ray UTC-11:00. Because UTC-11:00 and UTC+13:00 are 24 hours apart.

At the very least, if November really is used to mean UTC-13:00 in some cases, it should be removed from the table because it is NOT in the same location as the normal usage of November timezone.

What a mess.

BrianDGregory (talk) 23:18, 25 July 2024 (UTC)

You can see it here, N has a star and the note is "Letter N is also used to designate zone -13; this is to provide for a ship in zone -12 keeping Daylight Saving Time." IIRC I left it out but an IP added it.

It's already noted down below the table like with J and L and so on. Mathnerd314159 (talk) 02:20, 26 July 2024 (UTC)