6. The French Revolutionary Calendar

The French Revolutionary Calendar

The French Revolutionary Calendar (or Republican Calendar) was introduced in France on 24 November 1793 and abolished on 1 January 1806. It was used again briefly during under the Paris Commune in 1871.

What does a Republican year look like?

A year consists of 365 or 366 days, divided into 12 months of 30 days each, followed by 5 or 6 additional days. The months were:

1. Vendémiaire7. Germinal
2. Brumaire8. Floréal
3. Frimaire9. Prairial
4. Nivôse10. Messidor
5. Pluviôse11. Thermidor
6. Ventôse12. Fructidor

The year was not divided into weeks, instead each month was divided into three décades of 10 days, of which the final day was a day of rest. This was an attempt to de-Christianize the calendar, but it was an unpopular move, because now there were 9 work days between each day of rest, whereas the Gregorian Calendar had only 6 work days between each Sunday.

The ten days of each décade were called, respectively, Primidi, Duodi, Tridi, Quartidi, Quintidi, Sextidi, Septidi, Octidi, Nonidi, Decadi.

The 5 or 6 additional days followed the last day of Fructidor and were called:

1. Jour de la vertu (Virtue Day)
2. Jour du génie (Genius Day)
3. Jour du travail (Labour Day)
4. Jour de l'opinion (Reason Day)
5. Jour des récompenses (Rewards Day)
6. Jour de la révolution (Revolution Day) (the leap day)

Each year was supposed to start on autumnal equinox (around 22 September)

How does one count years?

Years are counted since the establishment of the first French Republic on 22 September 1792. That day became 1 Vendemiaire of the year 1 of the Republic. (However, the Revolutionary Calendar was not introduced until 24 November 1793.)

What years are leap years?

Leap years were introduced to keep New Year's Day on autumnal equinox. But this turned out to be difficult to handle, because equinox is not completely simple to predict. Therefore a rule similar to the one used in the Gregorian Calendar (including a 4000 year rule. It was to take effect in the year 20. However, the Revolutionary Calendar was abolished in the year 14, making this new rule irrelevant.

The following years were leap years: 3, 7, and 11. The years 15 and 20 should have been leap years, after which every 4th year (except every 100th year etc. etc.) should have been a leap year.

[The historicity of these leap year rules has been disputed. One source mentions that the calendar used a rule which would give 31 leap years in every 128 year period. Additional information is very welcome.]

How does one convert a Republican date to a Gregorian one?

The following table lists the Gregorian date on which each year of the Republic started:

Year1: 22 Sep 1792Year8: 23 Sep 1799
Year2: 22 Sep 1793Year9: 23 Sep 1800
Year3: 22 Sep 1794Year10: 23 Sep 1801
Year4: 23 Sep 1795Year11: 23 Sep 1802
Year5: 22 Sep 1796Year12: 24 Sep 1803
Year6: 22 Sep 1797Year13: 23 Sep 1804
Year7: 22 Sep 1798Year14: 23 Sep 1805

To convert dates Click Here

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