The French Republican Calendar


The French Republican calendar was instituted in October 1792 as part of a move away from the establishment and the Christian systems that signified the old regime. The calendar was deemed to have begun on the autumnal equinox of that year, i.e. 22nd September 1792, that being named Year 1 of the Revolution. The calendar was modelled on the Egyptian calendar of 12 months of 30 days each, followed by five or six epagomenal days to keep it synchronised with the solar year. The months were given rather poetic names by writer Fabre d'Églantine (who was later guillotined for his alleged part in a conspiracy), based upon the agricultural and meteorological year in France. The names were also given endings that depended upon the season that they belonged to, i.e. -aire for the autumn months, -ôse in winter, -al in spring and -dor in summer. The months are listed later with their equivalent dates in the Gregorian calendar.

Leap Years

There is contention as to what rules would have been employed for the application of leap years had the calendar continued in official use after year 14. The rule for leap years was originally that the first day of each year would be the day of the autumnal equinox. This meant that although usually leap years would be four years apart, every now and then there would be a five-year gap, meaning that it would not be possible to identify a year as being a leap year if the year is evenly divisible by four. However, then the problem is deciding what rule to actually use, and whether the leap years would then align with those in the Gregorian calendar or not.

The first few leap years, then, took place in years 3, 7 and 11. This would have continued with years 15 and 20 but the calendar was abolished in year 14. The simplest method would have been to apply the same rules as in the Gregorian calendar from year 20, i.e. leap years would occur the same years in each calendar. However, when the calendar was first set up it was stated that the first day of the year should fall on the day of the autumnal equinox. This is the rule that I have employed on the main page, and it ensures that the calendar keeps step with the seasons, as had been originally intended. Under this system years 218 (2009-10) and 222 (2013-14) will be leap years with 366 days.

The Months

The following table shows the names of the months along with the dates that they begin in most years:

Month Meaning Usual start dates
Vendémiaire (grape harvest) 22 Sep
Brumaire (fog) 22 Oct
Frimaire (frost) 21 Nov
Nivôse (snow) 21 Dec
Pluviôse (rain) 20 Jan
Ventôse (wind) 19 Feb
Germinal (germination) 21 Mar
Floréal (flowering) 20 Apr
Prairial (pasture) 20 May
Messidor (harvest) 19 Jun
Thermidor (heat) 19 Jul
Fructidor (fruit) 18 Aug

Complementary Days

The extra days, or les jours complémentaires, following the standard 12 months were given names as shown in the table below, along with their dates:

Day Meaning Usual dates
Jour de la Vertue (virtue) 17 Sep
Jour du Génie (talent) 18 sep
Jour du Travail (labour) 19 Sep
Jour de l'Opinion (opinion) 20 Sep
Jour des Récompenses (honours) 21 Sep
Jour de la Révolution (revolution) -