The French Revolutionary Calendar or French Republican Calendar is a calendar proposed during the French Revolution, and in use by the French government for 13 years from 1793. It was abolished by Napoléon partly to appease the Catholic Church, which opposed the calendar because it abolished the Sabbath and saints' days.

It was designed by the politician and agronomist Charles Gilbert Romme, although is usually attributed to Fabre d'Églantine, who invented the names of the months. The calendar was adopted by the Jacobin-controlled National Convention on October 24, 1793.

Years appear in writing as Roman numerals (usually), counted from the beginning of the 'Republican Era', beginning on September 22, 1792 (the day of the proclamation of the French First Republic, one day after the Convention abolished the monarchy). As a result the calendar is based on a date one year before it was actually adopted. The new year began on the autumnal equinox. There were 12 months, each divided into three ten-day weeks called décades. Each day was divided into ten hours, each hour into 100 decimal minutes and each decimal minute had 100 decimal seconds. Clocks were manufactured to display decimal time of day, but it did not catch on and was abandoned in 1795.

Napoléon finally abolished official use of the calendar on January 1, 1806 (in fact at midnight, the 10 nivôse year XIV aka December 31, 1805), thirteen years after its introduction. However, it was to be used again during the brief Paris Commune in 1871 (year LXXIX).

Many conversion tables and programs exist, largely created by genealogists. Some enthusiasts in France still use the calendar, more out of historical re-enactment than practicality.

The legal texts that were adopted when the Revolutionary Calendar was official and are still in force in France have kept their original dates for citation purposes.

The months

Revolutionary Calendar year began in autumn equinox and had twelve months of 30 days each, which were given new names based on nature:

• Autumn:
  • Vendémiaire (from Latin vindemia "vintage") Starting Sept 22, 23 or 24
  • Brumaire (from French brume, "mist") Starting Oct 22, 23 or 24
  • Frimaire (From French frimas, "frost") Starting Nov 21, 22 or 23
• Winter:
  • Nivôse (from Latin Nivosus, "snowy") Starting Dec 21, 22 or 23
  • Pluviôse (from Latin pluviosus, "rainy") Starting Jan 20, 21 or 22
  • Ventôse (from Latin ventosus, "windy") Starting Feb 19, 20 or 21
• Spring:
  • Germinal (from Latin germen, "seed") Starting Mar 20 or 21
  • Floréal (from Latin flor, "flower") Starting Apr 20 or 21
  • Prairial (from French prairie, "meadow") Starting May 20 or 21
• Summer:
  • Messidor (from Latin messis, "harvest") Starting Jun 19 or 20
  • Thermidor (from Greek thermos, "hot") Starting Jul 19 or 20
  • Fructidor (from Latin fructus, "fruits") Starting Aug 18 or 19

Note that the English names are approximate, as most of the month names were new words coined from similar French, Latin or Greek words. The endings of the names are grouped by season.

The days of the year

Instead of each day having a Saint as in the Catholic Church's calendar, each day has a plant, a tool or an animal associated with it.

Autumn

Winter

Spring

Summer

The ten days of the week

The month divides into 3 "weeks" each of ten days, named simply:

• primidi
• duodi
• tridi
• quartidi
• quintidi
• sextidi
• septidi
• octidi
• nonidi
• décadi.

Left-over days

Five left-over days (six in leap years) were used as national holidays at the end of every year. These were known at first as Les Sans-Culottides (after the sans-culottes), and after the year III (1795) as les jours complémentaires:

• La Fête de la Vertu "Virtue Day" on Sept 17 or 18
• La Fête du Génie "Talent Day" on Sept 18 or 19
• La Fête du Travail "Labor Day" on Sept 19 or 20
• La Fête de l'Opinion "Opinion Day" on Sept 20 or 21
• La Fête des Récompenses "Rewards Day" on Sept 21 or 22
• La Fête de la Révolution "Revolution Day" on Sept 22 or 23 (Leap years)

Critiques and shortcomings of the calendar

Leap years in the calendar are a point of great dispute, due to the contradicting statements requiring the year to start on the Autumnal Equinox while adding a leap day every 4 years (like the Gregorian Calendar). The years III, VII, and XI were observed as leap years, and the years XV and XX were also planned as such. However, an algorithm for determining leap years after year XX was never developed. As such, attempts to extend the calendar beyond year XIV often use differing methods of determining leap years. Most such attempts use a form of the Gregorian method (with or without a proposed 400-year rule in which every year divisible by 400 would be a non-leap year). Alternative systems included one that would have excluded leap years on years divisible by 128, and also one which would have divided each century into four "quarters" of 25 years each, with the 2nd, 6th, 10th, 14th, 18th and 22nd years of each "quarter" being leap years (creating a scenario whereby four times each century the leap years would be spaced five years apart instead of four, from the 22nd year of one quarter to the second year of the next); in addition, every fourth year ending in "00" would also be a leap year, thus exactly echoing the Gregorian practice of having 97 out of every 400 years be leap years.

The calendar was abolished because the Catholic Church strongly opposed it as an attempt to rid the calendar of all Christian influences; because having a ten-day work week gave workers less rest (one day off every ten instead of one day off every seven); because the equinox was a mobile date to start every new year (a fantastic source of confusion for almost everybody); and because it was incompatible with the secular rhythms of trade fairs and agricultural markets.

Perhaps the most famous date in this calendar was immortalised by Karl Marx in the title of his pamphlet, The 18th Brumaire of Louis Napoléon (1852). The 18 Brumaire (November 9, 1799) is considered the end of French Revolution. Another famous revolutionary date is 9 Thermidor, the date the Convention turned against Robespierre, who, along with others associated with the Mountain, was guillotined the following day. (See Glossary of the French Revolution for other significant dates under this calendar.)

Emile Zola's novel Germinal takes its name from the calendar, as does the dish, Lobster Thermidor.

It is notable that with the removal of religious influences this "universal" calendar was in fact made particular to France, since the descriptive month names would range from slightly to completely inaccurate when used in other climates (most obviously in the Southern Hemisphere). Also, the Autumnal Equinox - the event used to mark the start of each new year - does not occur on the same calendar date all over the world (based on local time), for example usually falling one day later in eastern Asia than in North America.

External links

• Summary of the Republican Calendar (http://prairial.free.fr/calendrier/sommaire.html) (fr es en eo pt de nl)
• Date converter for numerous calendars, including this one (http://www.calendarhome.com/converter)
• Abstract of an article on reactions to the Republican Calendar (http://www3.oup.co.uk/french/hdb/Volume_15/Issue_01/)