Talk:Gregorian calendar

Summarize Timeline Top Qs Fact Check

HI JMF. You have removed my edit from the lead with the justification:

"... it would be due in the Julian calendar article but it is undue in this one. Comparison with the (far more popular) Islamic calendar would be more due and I doubt we would have to include that."

I beg to disagree. Both the Julian and Gregorian are Christian calendars, so it does concern Christians calculating festival dates, and people from the Western world trying to figure out "old style" dates they come across. Many Eastern Orthodox Christians live by the "new style" calendar, but still celebrate their holidays by the "old style" one. For all these millions of people, having the "new date = old one + 13" rule somewhere handy is extremely useful. That's why I put it in the lead. Adding it also to the lead of the Julian calendar article is of course a good idea.

Muslims are a different category altogether, and Muslim calendar(s) are so fundamentally different, that no easy rule of thumb can be offered. Now because the Muslims can't have one, must we deny the Christians one as well? I absolutely don't see the logic in that. Considering your rational approach to things, I guess you just didn't actually fully think it through this time. Can we please agree to put it back in? Thanks. Arminden (talk) 19:33, 9 July 2025 (UTC)

Per WP:LEAD, items in the lead should summarise the essential points in the body. For an article of this size, that means a major section with subsections. What we have is a lot of material about why the JC was flawed and what was done about it from the mid 16th century to the early 20th century. The current conversion factor is the skin on the icing on that cake.

Per WP:DUE, the material should clearly be important and relevant to most readers and proportional in its scope. With all due respect, a very small proportion of readers of the Gregorian calendar article really have any interest in the current relation between dates in the Julian calendar and those in the Gregorian. The number of users of the JC is tiny, minuscule compared to users of the GC and tiny compared to users of the IC. Yes, it should be mentioned, but not in the lead. (And yes it would be equally undue to give the conversion to and from the Islamic calendar.) Conversely, as I said tersely in my edit summary, it would be an entirely due addition to the lead of Julian calendar, but I notice that you haven't done that. I would expect the Orthodox Christians to start from there, not from here. I assume you will do that now.

BTW, it is a relevant fact that Christians of whatever hue are a minority of the users of the GC. 𝕁𝕄𝔽 (talk) 21:04, 9 July 2025 (UTC)

Thank you. I still disagree - it was one short sentence, offering useful practical advice. To whom? Over 120 million members of churches going by the JC, plus all the pilgrims & visitors who visit their countries, among those countries being the one obviously major destination, the Holy Land with all the main holy sites, and the All-Pravoslavnic Russia. While being there, only the JC counts. The pool of potential pilgrims from the entire Eastern Orthodox Church amounts to 230 million people, and lots of them do go on pilgrimage. Peanuts?

I'm not presuming to know which of the two articles, JC or GC, those people might go to first. True is that the English version would not be the first choice of many. It's as true though that many "small(er) languages" simply translate the enWiki article, which will always be much more elaborate than any self-made one, as I've just noted with the Romanian article. So enWiki is always sure to at least be a main source for all others.

I'm thinking in practical, reality-facing terms. I don't know any of those Wiki abrreviations and I truly believe not to need them: the Wiki principles I know well, as I do encyclopedic standards & practices (I've grown up among encyclopedias in 3-4 languages, and using or perusing through them constantly). Wiki adds a new aspect, it's constantly updated and serves immediate needs, also on the go, unlike the thick Meyer's, Larousse or Britannica tomes.

Pls check the numbers:

"The Orthodox Churches of Jerusalem [0.5 M], Russia [110 M], Serbia [10 M], Montenegro [?], Poland [?] (from 15 June 2014), North Macedonia [?], Georgia [?], and the Greek Old Calendarists and other groups [?] continue to use the Julian calendar..."

But I'm not counting on a change mind, so I'll follow your advice and edit the JC calendar. Cheers, Arminden (talk) 00:03, 10 July 2025 (UTC)

Well let's see if other editors chip in. If the consensus disagrees with me, I will concede. But the fundamental point is that, in big articles like this one, every sentence needs to earn its keep and that stricture applies most especially to the lead section. 𝕁𝕄𝔽 (talk) 01:15, 10 July 2025 (UTC)

Sorry for the abbreviations, they are mine. GC = Gregorian Calendar, JC = Julian Calendar, IC = Islamic Calendar. 𝕁𝕄𝔽 (talk) 01:17, 10 July 2025 (UTC)

I'm a big user of abbreviations myself, I just mentioned the linked Wiki abbreviations as not my thing. Yours were actually quite generic, but I'm a bit allergic to them. Arminden (talk) 13:23, 10 July 2025 (UTC)

My opinion is this does not belong in the lead. Whether it's useful is irrelevant; the question is whether it is encyclopedic and conforms to Wikipedia guidelines, especially MOS:LEAD. A tidbit about how to convert between one particular calendar and the subject calendar does not seem due for the lead, and as it was placed, it seems a distracting non-sequitur. Also, this conversion is already stated in the infobox; if someone is looking for a quick guide to conversion, it seems they're more likely to see it in the table in the infobox, rather than reading through the whole lead. CodeTalker (talk) 02:17, 10 July 2025 (UTC)

Hi. That argument I'm much more open to, except that

- my edit mentioned that it's for now only (1900-2100), otherwise why would anyone bother to create a new calendar if it were forever a constant difference (D = J + 13)? Still concise, but containing everything that's needed, either stated or implied.

Year in various calendars (retrospectively inserted subsection header)

- I'm only using the phone, and the phone layout is such that one only sees the first lead paragraph before needing to do a lot of scrolling down.

- There are 2 infoboxes. The 1st is endless. The 2nd is only confusing things, apparently contradicting the +13 rule. To fit, it needs constant updating. I pressed on "refresh" and what comes up? "Purge this page"! Purging sounds FAR too scary & radical, so I give up, as 99% of the users would.

Conclusion: no good, period. Appears to be self-contradictory, not user-friendly (technical), in short: useless. Remember: the public is not the academics. I'm not a friend of dumbing down, may Zeus forbid, but of being user-friendly and practical-minded? You bet. Arminden (talk) 13:40, 10 July 2025 (UTC)

I see what you mean about the huge "2025 in various calendars" infobox, when viewed on mobile as the large majority of our readers do. Its purpose is to show that the GC is one of many. In my opinion, it needs to be moved down. I'll have a look and maybe Be Bold if I can find a better home for it.

The Today infobox is a lot more reasonable and useful but it needs to say somewhere that the date is reset automatically at 00:00 (UTC). If you live in NZ, for example, you'll have to wait. Or at least I think that this is what is happening! Which time zone are you in? 𝕁𝕄𝔽 (talk) 15:21, 10 July 2025 (UTC)

Meanwhile, I have boldly moved the giant table of other calendars down to the See Also section, which is the most logical place for it. --𝕁𝕄𝔽 (talk) 16:23, 10 July 2025 (UTC)

"This image shows the difference between the Gregorian calendar and the astronomical seasons....Each point is the date and time of the June solstice in that particular year." But which points are for the calendar and which are for the astronomical seasons? 199.192.151.199 (talk) 14:58, 7 August 2025 (UTC)

The word "difference" in the caption is a bit confusing. It's up to the reader to look at the date and time from the graph and subtract the "ideal" date and time of the solstice, that is, the date & time the designers of the calendar were aiming for. We know they were aiming to place the March equinox on March 21, but we don't know what time of day or place they had in mind (Rome? Jerusalem?). So we can't actually do the subtraction to get a number of hours the solstice is "off". Jc3s5h (talk) 12:26, 8 August 2025 (UTC)

Summarize Timeline Top Qs Fact Check

On 23 October 2025 Cimumetupp (talk · contribs) added this paragraph:

The number of days in a 400-year Gregorian cycle is divisible by 7 (146,097 equals 7 × 20,871), meaning the 400-year cycle is also a complete cycle of the days of the week. Consequently, the calendar repeats exactly every 400 years, with dates falling on the same days of the week. [The word "equals" substituted for the equals sign because of technical limitations]

The first problem with this addition is it is redundant; the preceding paragraph in the "Description" section already begins with

Calendar cycles repeat completely every 400 years, which equals 146,097 days.^[a]

The second paragraph is false. The Gregorian calendar includes the Easter calculation. As the article already states, a full cycle, including the dates of Easter, lasts 5,700,000 years. Because the added paragraph fails to mention the Easter calculation, it is false. Jc3s5h (talk) 19:07, 23 October 2025 (UTC)

Version discussed:

The number of days in a 400-year Gregorian cycle is divisible by 7 (146,097 = 7 × 20,871), meaning the 400-year cycle is also a complete cycle of the days of the week. Consequently, the calendar repeats exactly every 400 years, with dates falling on the same days of the week.

Taking the Easter ambiguity into account:

The number of days in a 400-year Gregorian cycle is divisible by 7 (146,097 = 7 × 20,871), meaning the 400-year cycle is also a complete cycle of the days of the week. Consequently, after each 400-year cycle, specific dates fall on the same days of the week. Cimumetupp (talk) 20:23, 23 October 2025 (UTC)

The version Taking the Easter ambiguity into account: isn't false anymore, but it's still redundant. The article already said the same thing in the preceding paragraph. Jc3s5h (talk) 21:22, 23 October 2025 (UTC)

Preceding paragraph:

Calendar cycles repeat completely every 400 years, which equals 146,097 days.^[b][c] Of these 400 years, 303 are regular years of 365 days and 97 are leap years of 366 days. A mean calendar year is ⁠365+97/400⁠ days = 365.2425 days, or 365 days, 5 hours, 49 minutes and 12 seconds.^[d]

In detail:

Calendar cycles repeat completely every 400 years, which equals 146,097 days. This means that a sequence of consecutive dates begins to repeat after 146,097 of them. For example, the sequence 23 Oct., 24 Oct., ... , 22 Oct. of the 146,097 consecutive dates and the sequence of the next 146,097 consecutive dates are identical.

The Julian Calendar cycle is 4 years, i.e. 365 × 3 + 366 = 1,461 days. This means that a sequence of 1,461 consecutive dates and the sequence of the next consecutive dates (of the same length) are identical.

However, the cycle of (Date, Day of the week) pairs is a separate matter.

1,461 = 7 × 208 + 5. This means that the Julian date cycle shifts the day of the week 5 days forward. Thus, the Julian cycle of (Date, Day of the week) pairs is 7 times longer, i.e. 4 × 7 = 28 years (1,461 × 7 = 10,227 days).

However, for the Gregorian calendar, the cycle of dates and the cycle of (Date, Day of the week) pairs are the same, because of 146,097 = 7 × 20,871. Cimumetupp (talk) 01:30, 24 October 2025 (UTC)

As I can't see a relevant WikiProject to notify and because it is about a proposal to replace the Gregorian calendar, be advised that I have proposed that Sexagesimal calendar be deleted. See Wikipedia:Articles for deletion/Sexagesimal calendar for rationale. 𝕁𝕄𝔽 (talk) 22:10, 14 December 2025 (UTC)

There is a discussion at talk:Julian calendar#Otherr calendars which affects this article. Please contribute there. 𝕁𝕄𝔽 (talk) 05:11, 23 April 2026 (UTC)