Talk:French Republican calendar

Metrology

I'd like to comment on the metric system. — Preceding unsigned comment added by ClioFR (talk • contribs) 19:14, 1 May 2018 (UTC)

Requested move 11 October 2018

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

Moved to French Republican calendar as proposed. After extended discussion, there is clear consensus for decapitalizing "calendar" in this title, but not for decapitalizing "Republican". bd2412 T 22:51, 27 October 2018 (UTC)

French Republican Calendar → French Republican calendar – Compliance with WP:TITLEFORMAT and consistency with Gregorian calendar, Julian calendar, Solar Hijri calendar, etc. The title with lower-case "calendar" was created straightaway as a redirect to the original, and current, article, when it would have been appropriate to move the original article to that title. Largoplazo (talk) 16:57, 10 October 2018 (UTC) --Relisting. Favonian (talk) 16:58, 17 October 2018 (UTC)

This is a contested technical request (permalink). Scarabocchio (talk) 11:31, 11 October 2018 (UTC)

It feels different. "White House" is not the same as "White house" .. the element of compound noun is broken by the suggested change. It shoul dbe discussed first. Scarabocchio (talk) 11:31, 11 October 2018 (UTC)

It looks like the move has been already made, though the above message implies that 7 days of discussion will be allowed!!! Scarabocchio (talk) 12:04, 11 October 2018 (UTC)

I've reverted the page move to allow a consensus to be formed. Iffy★Chat -- 13:08, 11 October 2018 (UTC)

• Support move to French Republican calendar per nom; policy seems clear here. Some sources use French republican calendar, but I don't support that; it is the calendar of the (first) French Republic. power~enwiki (π, ν) 20:49, 11 October 2018 (UTC)
• Oppose. This is a specific, and deliberate, human construct that needs a compound noun (like the "British Museum") rather than an instance of a generic object (like "Islamic art museum"). Scarabocchio (talk) 03:22, 12 October 2018 (UTC)

the Ngram argument below seems to leave no room for any discussion that it should remain unchanged. Opposition reluctantly withdrawn. But it is a calendar of the (first) French Republic, as power~enwiki points out. This is the style used in the official name of the country. Scarabocchio (talk) 15:47, 15 October 2018 (UTC)

'French Republic' is a proper name and should be capitalised, but 'French republican' is not. Rough descriptions of the names of institutions are not capitalised, only the actual names themselves. Per MOS:CAPS, if something is not 'consistently capitalised in a substantial majority of independent, reliable sources', we don't capitalise it. Clearly, such is not the case for 'French Republican'. RGloucester — ☎ 01:29, 16 October 2018 (UTC)

• I'd go even further and suggest 'French republican calendar' per WP:NCCAPS. We do not capitalise rough descriptions of the names of institutions (in this case, French Republic). See MOS:POLITICALUNITS. Above arguments about 'compound nouns' do not jive with the relevant guidelines, that is, WP:NCCAPS. This is clearly not a proper name. If we look at Ngrams, we see that all three styles have been used to various degrees over the past two hundred years. According to MOS:CAPS, only items that are "consistently capitalised in a substantial majority of independent, reliable sources" are capitalised on Wikipedia. This is not the case here...as seen in the Ngram. Therefore, we default to lowercase. RGloucester — ☎ 21:41, 12 October 2018 (UTC)

See Proper adjective. --Nike (talk) 08:32, 16 October 2018 (UTC), Quartidi 24 Vendémiaire an CCXXVII à 3 heures 62 minutes décimales t.m.P.

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Specific day of abolishment

The article currently states: "The calendar was abolished in the year XIV (1805)." But it does not give a clear day of when another calendar took its place. It's clear that it went in use on 1792-09-22 (Gregorian) as that equals the first day of the first year. This site: 1789-1815 calendars - table de concordance implies that it was used until a day in the 3rd month (frimaire) of the year XIV. However, due to the lack of links beyond year IX, we can't see the exact date. Is there any source providing an official day when the switch happen?
Liggliluff (talk) 07:35, 14 August 2020 (UTC)

The artIce states: "As the rapporteur of the commission, Charles-Gilbert Romme presented the new calendar to the Jacobin-controlled National Convention on 23 September 1793, which adopted it on 24 October 1793 and also extended it proleptically to its epoch of 22 September 1792."

It then states: "Napoleon finally abolished the republican calendar with effect from 1 January 1806 (the day after 10 Nivôse Year XIV)…"

--Nike (talk) 05:00, 15 August 2020 (UTC) (Octidi 28 Thermidor an CCXXVIII à 2 heures 6 minutes décimales t.m.P.)

As per this page the decree in question is dated 22 Fructidor XIII, or 9 September 1805, to take effect 1 January 1806. Arcorann (talk) 15:00, 9 September 2020 (UTC)

Where does this “Continuous” rule come from?

I get that deciding when leap years occur in the “real” French Republican calendar is not easy.

As I understand the history:

The decree of Saturday 5 October 1793 establishing the French Republican calender contradicts itself on the issue of the occurrence of leap days.

• The first articles describe how the first day of the year is the day on which the autumnal equinox falls at the Paris Observatory.
• But articles X and XVI describe a leap day, called Day of the Revolution, every 4 years. A period of 4 years ending in a leap day is called a Franciade.

A controversy ensued. Yet a general consensus formed at the time, with the equinox rule prevailing over the a-leap-day-once-every-4-years rule.

But this consensus led to another issue. Mr. Jean-Baptiste Joseph Delambre, an astronomer, pointed out after the introduction of the French Republican calendar that according to his calculations the equinox of Monday 23 September 1935 was to take place about 20 seconds before midnight, with an uncertainty of several minutes. So it wasn’t yet clear to him, an astronomer, whether year CXLIV would start on that day or the next. (It turned out that autumnal equinox took place on Monday night 23 September 1935 at 23:48 in Paris, local time. So Mr. Delambre was about 11 minutes off, but his calculations had the day right nonetheless.) Clearly, an arithmetical rule would be preferable for the calendar to be more predictable.

Hence Mr. Charles-Gilbert Romme, the head of the commission that introduced the French Revolutionary calendar in the first place, proposed already in year III a new rule: French Republican years would be leap years if they are divisible by 4, except not if they are divisible by 100, except too if they are divisible by 400, except not if they are divisible by 4000. According to this proposal, the first leap year would be year IV. His project of decree was discussed in committee on 19 Floréal III (Friday 8 May 1795) (less than 5 months before the end of year III which would change from leap year into common year, if the proposal were enacted).

But Mr. Romme supported the demands the Montagnard uprise of 1 Prairial III (Wednesday 20 May 1795). The revolt failed, and Mr. Romme was among those sentenced to death. Before the sentence could be executed, he committed suicide on 29 Prairial III (Wednesday 17 June 1795). His project of decree amending the leap year rule died with him: it never got enacted into law.

Without the enactment of Mr. Romme's project of decree, year III was the first leap year, because of the equinox rule. With some creative thinking, this decision could still be explained in accordance to the once-every-4-years rule: the first Franciade simply started one year before the epoch. Thereafter, years VII and XI were leap years: neatly and orderly 4-year Franciades apart.

The Bureau des Longitudes held on to the consensus that the equinox rule prevails over the every-4-years rule, and published official guidance that years XIX and XXIII would be common years, and years XX and XXIV would be sextile years.

But on 22 Fructidor XIII (Monday 9 September 1805), emperor Napoleon Bonaparte sings the senatory consultary that abroges the Republican calendar on 11 Nivôse XIV (Wednesday 1 January 1806), and restores the Gregorian calendar that day.

In Paris, the French Republican calendar was briefly reinstated for a short period in 1871 (year LXXIX).

So, how to decide which years are leap years from XIV onwards?

• Since the equinox rule was in force immediately prior to the abrogation of the French Republican calendar, this rule is the most obvious.
• Or: one could follow Mr. Romme’s rule, even though it wasn’t followed during the time that the French Republican calendar was in actual use (at least from the Day of the Revolution in year III onwards).
• Or: one could follow the late-19th-century proposal of Mr. Johann Heinrich von Mädler, another astronomer, in which years from year XX onwards are leap years if they are divisible by 4 but not by 128. Prior to year XX, years III, VII, XI and XV are leap years (and year XIX is a common year).
• Several concordance tables did not agree with the equinox rule prevalence over the once-every-4-years rule, and predicted years XIX, XXIII, XXVII, etc. to be leap years. Especially lawyers and notaries with a preference for ease and predictability used such concordance in contracts, usually mentioning explicitly that future dates in their documents are to interpreted according to the once-every-4-years rule, even if this does not agree with the common or legal calendar interpretation in that future time.
• Added 7 November: I came across an approximation to the equinox rule by Jean-Baptiste Joseph Delambre with vernal equinoxes that occur every 365,2420463 days exactly. — Preceding unsigned comment added by Adhemar (talk • contribs) 19:40, 7 November 2020 (UTC)

The article describes another possibility: the “Continuous” rule. What this rule comes down to is: the leap years according to the Continuous rule are the years prior to the leap years according to Mr. Romme’s rule.

I can’t see where that rule comes from. I find absolutely no reference to such a rule in the cited sources (either Renouard (1822) or the archived project of decree of Romme at prairial.free.fr). — Adhemar (talk) 22:53, 5 October 2020 (UTC)

As one can see in the references, the so-called “Continuous” rule was followed in some concordances, and by various modern-day users, which is what you call the "once-every-4-year" rule, even though Romme also added a leapday once every 4 years. Unlike Romme, this rule is continuous with historical leapyears. --Nike (talk) 02:52, 8 October 2020 (UTC) ( Septidi 17 Vendémiaire an CCXXIX à 1 heure 25 minutes décimales t.m.P.)

Thank you, Nike. I appreciate your reply. I’m afraid I did not express myself clearly enough. I do not dispute that there are concordances such as this one (upto year XXV) and this one (upto year XLII) printed before or shortly after the abrogation of the French Republican calendar that followed the continued “once-every-4-year” rule, with leap years in years where (French Republican year number) mod 4 = 3. But using that rule, year CCXXIX would start on Thursday 24 September 2020, not on Tuesday 22 September 2020 as the table in the article states. The difference of two days is explained by the exceptions for years XCIX and CXCIX. Under Romme’s rules, years C and CC would not have been leap years. What I can’t find is a reference to a concordance that follows or a document that describes the “Continuous” rule with the every 4-but-not-100-but-too-400-but-not-4000 exception — or some other form of “most century years” exception, as it is described and applied in the article. (Other than the ones that describe Mr. Charles-Gilbert Romme’s project of decree, which provided leap years in the most years with year numbers divisible by 4, rather than the years preceeding them, that is). — Adhemar (talk) 16:31, 8 October 2020 (UTC)

The rule you are referring to is not a rule de jure, but de facto. It is, in point of fact, the rule most often used by modern users of this calendar. I am not aware of any concordances or annuaires for years after IC, but this method has been used by software applications since at least the early third century. You might try searching software manuals. I only know of one example of the 128-year method. --Nike (talk) 07:28, 6 November 2020 (UTC) (Sextidi 16 Brumaire an CCXXIX à 3 heures 17 minutes décimales t.m.P.)

Thank you. I must use different softwares than you do, because the different softwares I know do not support this rule — nor the 128-year von Mädler rule, for that matter. The only ones I have come across to are: (1) the astronomical rule; (2) the Romme rule; (3) the every-4-year rule without century year exception (which is only exactly as accurate as the Julian calendar); and (4) approximations for (1) such as the one by Jean-Baptiste Joseph Delambre. Formulas for only (1) and (2) are included in Calendrical Calculations by Edward M. Reingold and Nachum Deshowitz, which is one of the standard works for calendar studies.

But thank you for confirming that the “Continuous” rule with the 4-but-not-100-but-too-400-but-not-4000 exception has no basis in historical decisions or documents, but something that somehow only found its way in modern software (that I do not know of). After all, “since the early third century” is since the mid-1990s or even the 21st century, Gregorian. If this is truly a rule used by modern users of this calendar, can references to modern software be provided? — Adhemar (talk) 19:31, 7 November 2020 (UTC)

I would like to see an example of description of rule (3), without century exceptions. Software I have seen uses the "continuous" method with Romme's modifications. I have not seen any historical sources which describe how future century years are to be dealt with in this scheme. I have also not seen any modern examples, which would differ from "continuous" dates by two days. Since the topic is converting contemporary dates, methods which are nowhere used now are irrelevant. Further, "continuous" dates are the only ones I have observed which are consistent with historical dates continuing after the Revolution, which were all in the First Century. If you have historical sources which say otherwise, please let me know, but the "continuous" method seems be one in use today.

BTW, the term "continuous" is original to this article, and may not be the best one. Perhaps "consistent" would be better, since it is consistent with historical dates given both before and after 1805. --Nike (talk) 05:07, 9 November 2020 (UTC) (Nonidi 19 Brumaire an CCXXIX à 1 heure 86 minutes décimales t.m.P.)

An example of software using this method may be found at Brumaire. It has been online over 20 years, I think. From the Brumaire manual:

Le logiciel respecte parfaitement la période historique (an 2 à an 14, pour les généalogistes), et applique le projet de Romme décalé d'un an, sans plus tenir compte de l'équinoxe vrai, ce qui provoque d'éventuelles différences d'un jour à partir de l'an 19, pour certaines années... Les années bissextiles ne sont pas les années multiples de 4 (comme prévu dans le projet de Romme), puisque dans la période historique, c'étaient les ans 3, 7 et 11. Les années bissextiles correspondent donc aux années précédant un multiple de 4.

The method is also used in their iOS app. --Nike (talk) 02:17, 10 November 2020 (UTC) (Decadi 20 Brumaire an CCXXIX à 1 heure 1 minute décimale t.m.P.)

Paris Commune

I note from French_Republican_calendar#History that "It was, however, used again briefly in the Journal officiel for some dates during a short period of the Paris Commune, 6–23 May 1871 (16 Floréal–3 Prairial Year LXXIX)." I assume that the Communards must have made a decision as to which of the above systems they would use in order to decide that 6 May 1871 was equivalent to 16 Floréal Year LXXIX. Would it be worth mentioning this in the article?

Sorry - I note that this was discussed at Talk:French_Republican_calendar/Archive_1#Use_in_1871 and Talk:French_Republican_calendar/Archive_1#The_leap_year_rule and according to the latter "the dates work out the same that year". Alekksandr (talk) 21:36, 25 December 2020 (UTC)

1800 not a Gregorian leap year

Does that cause something to be knocked a day off? The French Revolurionary calendar started in 1792, and Gregorian wasn't officially restored until 1806. Carlm0404 (talk) 07:24, 17 December 2021 (UTC)