Template talk:Infobox calendar date today

Byzantine calendar day of month should be the same as the Julian, not the Gregorian

The Byzantine calendar was the same as the Julian, one leap year in four invariably. The only difference between them is the epoch. Am I right or am I right? 𝕁𝕄𝔽 (talk) 20:23, 28 January 2025 (UTC)[reply]

Your statement conforms to the established facts. The Byzantine line should be removed from this template until someone implements it correctly. I took a quick look at {{JULIANCALENDAR}}, and it's not trivial to use it as a basis for a new template. I have a bit of interest in attempting it, but realistically I don't think I'll be able to invest the necessary time. Indefatigable (talk) 21:49, 28 January 2025 (UTC)[reply]

Admittedly it was monkey see, monkey do, but I hacked the algorithm at {{JULIANCALENDAR}} by changing the fudge factor at the end. Am I wrong or am I wrong?

. It seems to work so I've made it live.

Alternatively, since it is no longer used anywhere, maybe we should just remove it? 𝕁𝕄𝔽 (talk) 13:35, 29 January 2025 (UTC)[reply]

I too was thinking about its inclusion, and I think we should set a guideline for this template that only calendars that are currently in use should be here. Otherwise more and more historical calendars will be added until the template becomes cluttered and unusable. The Byzantine year count I don't think is used by any churches or governments anymore, so if we adopt that guideline we'd have to remove it. Indefatigable (talk) 16:41, 29 January 2025 (UTC)[reply]

Yes, I agree. Otherwise it will rapidly become undue in the articles where it is used and just be deleted. So I will be bold now and remove that entry. If anybody disagrees, well they know what to do. 𝕁𝕄𝔽 (talk) 17:05, 29 January 2025 (UTC)[reply]

When does "today" start?

Do readers in Sydney get their new weekday and date displayed, although it is still yesterday in London? 𝕁𝕄𝔽 (talk) 11:36, 2 February 2025 (UTC)[reply]

The template uses a mix of magic words and the #time parser functions - all of which uses UTC time as that is what English Wikipedia is configured for. Harryboyles 14:00, 2 February 2025 (UTC)[reply]

The reason I asked is that the template is used in a number of calendar articles whose day, most noticeably the New Year's Day, starts many hours ahead of UTC. Does it matter? (it would be better not to clutter the display with detail if we don't have to). --𝕁𝕄𝔽 (talk) 16:19, 2 February 2025 (UTC)[reply]

Just to wrap this one up, "Today" starts invariably at UTC+00. As explained below, there is no current "ready to use" function that will adapt the display to the reader's time zone. 𝕁𝕄𝔽 (talk) 10:24, 14 July 2025 (UTC)[reply]

Call for documentation

Although this online application is very useful and is used on many WP pages, it is completely unsourced.

Nothing is mentioned about the used algorithms, nor is any literature cited.

In the case of the Islamic calendar, it should be mentioned that it appears to be based on the tabular Islamic calendar (which of the many versions?) and that the displayed date can be one, or even two days in variance with other Islamic calendar date converters. AstroLynx (talk) 10:17, 27 June 2025 (UTC)[reply]

I made the Coptic calendar one, so I can tell you where it comes from. The algorithm is admittedly my own, but I was trying to reverse engineer the one used on Coptic Reader, which is an app officially developed and endorsed by the Coptic Orthodox Diocese of the Southern United States. I also made the Julian calendar one, but the algorithm for that comes from here, which is referenced in its documentation.🎸平沢唯を愛しています🐱 (talk) 07:41, 18 July 2025 (UTC)[reply]

Thanks for the info on the Coptic and the Julian calendars. Hatcher's paper is very useful for simple arithmetical calendars, see also his subsequent paper in which he gives a generalized formula for arithmetical calendars. AstroLynx (talk) 08:43, 18 July 2025 (UTC)[reply]

@Gonnym:, can you do the needful please? ~~or at least say where #time and its arguments like xij can be found so that someone else can do it?~~ --𝕁𝕄𝔽 (talk) 15:40, 29 June 2025 (UTC)[reply]

Struck request for info about #time as I've found it at mw:Help:Extension:ParserFunctions##time: its purpose seems to be formatting ao doesn't do much to resolve the request. --𝕁𝕄𝔽 (talk) 15:47, 29 June 2025 (UTC)[reply]

With the help of Jonesey95, I believe that the requirement for documentation has been met and the "ticket" may be considered to be closed. (The info was in mw:Help:Extension:ParserFunctions##time: all along – I failed to spot it in the blue column down the right hand side of that page.) 𝕁𝕄𝔽 (talk) 11:12, 2 July 2025 (UTC)[reply]

The reference to Dershowitz & Reingold's Calendrical Calculations at the bottom of template documentation sheet suggests that all the adopted algorithms in this template can be found in this well-known work but where is this explicitly stated? Is it possible to view the actual code of the various algorithms to verify whether it is indeed based on CC or on other source(s)? AstroLynx (talk) 21:04, 16 July 2025 (UTC)[reply]

I found the relevant code at https://gerrit.wikimedia.org/g/mediawiki/core/+/90de8a15146dd7301cc948795fbfffe1f3b73b04/includes/language/Language.php#1400. The comments suggest that the code has been gathered from a variety of online sources. It's certainly not from Calendrical Calculations. Arcorann (talk) 14:08, 17 July 2025 (UTC)[reply]

Thanks for the link, this is extremely useful though it will take some time to properly digest all this information.

Perhaps this link should be included at the bottom of the template documentation sheet for those who wish to know the inner workings of the template.

The Dershowitz & Reingold reference can stay as a general introduction on calendar computations but it should be made clear that the algorithms used in this template are not necessarily based on the algorithms listed in this work. AstroLynx (talk) 14:57, 17 July 2025 (UTC)[reply]

Meanwhile I have revised the template/doc page to redact my unfounded assertion. My bad. 𝕁𝕄𝔽 (talk) 20:28, 17 July 2025 (UTC)[reply]

Islamic date only

Today in the Islamic calendar
(using tabular method):

22 Muharram 1447 AH
(= 18. July 2025)
[update]

Now that the sourcing problem has been partially answered it may be useful to note that when only the Islamic date is desired one could use the following wikicode which was modified from the German Wikipedia.AstroLynx (talk) 08:49, 2 July 2025 (UTC)[reply]

True but one of the motivations for creating this "Today" infobox was to put a date in any system in an overall context. Previously we had a mess of different styles and subjective selections of what to include and what to omit. So I would hope that we don't slip back into that bad habit. 𝕁𝕄𝔽 (talk) 11:08, 2 July 2025 (UTC)[reply]

@AstroLynx: Please don't paste code blobs into the talk page; they are difficult to format correctly and cannot be tested directly. Instead, please edit the sandbox, per WP:TESTCASES. --Redrose64 🌹 (talk) 18:11, 2 July 2025 (UTC)[reply]

"Today (UTC)"?

There seems to be a problem with the dates appearing to be "wrong" for readers significantly east of 0° (Asia, Australasia and Oceania especially). Before I ask for help at Technical, could someone from that area report back what they see? 𝕁𝕄𝔽 (talk) 16:32, 10 July 2025 (UTC)[reply]

With thanks to Javier1957, it is now clear it takes until noon New Zealand time (UTC+12:00) for the 'day' to change over. So the problem occurs worldwide but is more obvious the further east you go from 0°, which is really a disservice to readers in Asia snd Australasia. That is the reason why I have added a note under the TODAY line to say that it is "at UTC+00" so that users don't waste time hitting refresh. I'll now search the doc for #time to see if there is a way to display local time if it can be fetched from the user's settings. I'm not optimistic . --𝕁𝕄𝔽 (talk) 14:55, 11 July 2025 (UTC)[reply]

Although #time has a local setting, it means local to a whole Wikipedia (i.e., not en.wiki). So this is the best we can do at present. 𝕁𝕄𝔽 (talk) 08:53, 12 July 2025 (UTC)[reply]

If you know the offset of a time zone, you can factor that in, as in {{#time: H:i, j F Y (e+11)|now + 11 hours}} → 19:43, 18 July 2025 (UTC+11) also {{#time: H:i, j F Y (e-5)|now - 5 hours}} → 03:43, 18 July 2025 (UTC-5). --Redrose64 🌹 (talk) 13:35, 12 July 2025 (UTC)[reply]

True but only when preconfigured, not responding dynamically according to the reader's current timezone. Setting it according to article used [e.g., Tehran for SH, Tel Aviv for AM] is certainly possible in the way you suggest, but IMO it wouldn't be more useful to Shias in Chicago or Jews in Jersey. (Ignoring the awkward detail that #time can't handle half-hour UTC offsets.) But thanks for the idea. Pity. 𝕁𝕄𝔽 (talk) 14:20, 12 July 2025 (UTC)[reply]

20:13, 18 July 2025 (UTC+11:30) --Redrose64 🌹 (talk) 17:20, 12 July 2025 (UTC)[reply]

"Refresh" removed

Following on from the discussions above and consequent addition of an explicit "at UTC+00" at the top, I have boldly removed the "refresh" option. It never updated the dates to match the reader's local time zone, which is what I suspect most people were trying to do. If anyone knows of a real-world purpose for it, please comment. --𝕁𝕄𝔽 (talk) 10:17, 14 July 2025 (UTC)[reply]

Inconsistency in mdy and dmy notation

The calendar date template currently expresses the calendar dates both in mdy notation (Gregorian, Coptic & Bengali) as in dmy notation (Islamic, Hebrew, Solar Hijri and Julian).

Should not one of either be chosen for consistency? AstroLynx (talk) 14:40, 14 July 2025 (UTC)[reply]

Yes, I agree. There is no obvious internal-to-Wikipedia basis to come down in favour of one form rather than the other, so we need to refer to external evidemce.

Google Gemini declares that dmy is used by far more people worldwide than is mdy.

Enough? 𝕁𝕄𝔽 (talk) 17:24, 14 July 2025 (UTC)[reply]

If other editors also agree that would be the best solution. AstroLynx (talk) 18:00, 14 July 2025 (UTC)[reply]

I just fixed it by making them all dmy. 🎸平沢唯を愛しています🐱 (talk) 00:25, 15 July 2025 (UTC)[reply]

Also, should the abbreviation for the calendar era go before or after the year number? Most of them had it after (like 2025 AD), but I think it's technically more correct to have it before (like AD 2025) so I changed the ones that had it after. 🎸平沢唯を愛しています🐱 (talk) 00:37, 15 July 2025 (UTC)[reply]