The French Republican Calendar: How Time was Different

The French Republican Calendar, also sometimes called the French Revolutionary Calendar, was a calendar created and implemented by the French Republic during the French Revolution from late 1793 to 1805 (and for 18 days by the Paris Commune in 1871). The French Republican calendar came about because the government wanted to distance itself from anything associated with the Ancien régime and religion. Thus, the government decreed on 24 November 1793 that the common era would be abolished.

French Republican calendar for the month Vendemiaire. Courtesy of Wikipedia.

The new Republic also instituted changes resulting in a new social and legal system, a new system for weights and measures, and a new calendar. The new calendar was influenced by Enlightenment ideas and created using the fundamental blocks of natural constants, multiples of ten, and Latin and ancient Greek derivations. They also decided that new French era would commence on 22 September 1792 (one day after the Convention abolished the monarchy) and they used the Roman Numeral I to indicate the first year of the republic.

Republican Calendar of 1792. Courtesy of Bibliothèque nationale de France.

The first year of the new French Republican calendar was slated to begin soon after the horrendous murder of the Princesse de Lamballe. The new calendar began at midnight between the 21st and 22nd of September 1792 and ended at midnight between the 21st and 22nd of September 1793. However, “the Republican Calendar was first used on the 26th of November, 1793, and was discontinued on the 31st of December, 1805, when the Gregorian Calendar was again used.”[2] One English paper wrote about France’s new Republican calendar in 1798 in not so pleasant terms:

“This was intended to root from the poor tyrannized people the very memory of religion; to dry up the only source of comfort they had left. They had been robbed of all they possessed in the world, and their inexorable tyrants wished to rob them of every hope in the next. Some say that this calendar itself was composed by an apostate priest; others that it was the work of a writer of farces named des Moulins.”[1]  

The new French Republican calendar was divided into twelve months, each month had 30 days, and the five extra days needed to complete the year were placed at the end of the last month. These five days were called “Fours complémentaires” and were used to celebrate festivals that obtained the name of “Sansculottides.” The extra five days were called Primidi (September 17), Duodi (September 18), Tridi (September 19), Quartidi (September 20), and Quintidi (September 21). In addition, “Leap-year, which was called an Olympic year, [was to] take place every four years,”[3] and the extra day associated with leap year was called Sextidi.

The twelve months were established as indicated in the following seasons:


  • Vendémiaire, from the French vendange, derived from Latin vindemia, “grape harvest” (September 22 to October 21)
  • Brumiaire from the French brume, “mist” (October 22 to November 20)
  • Frimaire from the French frimas, “frost” (November 21 to December 20)


  • Nivôse from the Latin nivosus for “snowy” (December 21 to January 19)
  • Pluviôse from French pluvieux, derived from the Latin pluvius, “rainy” (January 20 to February 18)
  • Ventôse from French venteux, derived from Latin ventosus, “windy” (February 19 to March 20)


  • Germinal from French germination (March 21 to April 19)
  • Floréal from French fleur, derived from Latin flos, “flower” (April 20 to May 19)
  • Prairial from French prairie, “meadow” (May 20 to June 18)


  • Messidor from Latin messis, “harvest” (June 19 to July 18)
  • Thermidor from Greek thermon, “summer heat” (July 19 to August 17)
  • Fructidor from Latin fructus, “fruit” (August 18 to September 16)

Another change was that the month was divided into décades and instead of weeks, the decades consisted of ten days called Primidi (first day), Duodi (second day), Tridi (third day), Quartidi (fourth day), Quintidi (fifth day), Sextidi (sixth day), Septidi (seventh day), Octidi (eighth day), Nonidi (ninth day), and Décadi (tenth day). Moreover, each day had a unique name and special meaning that was associated primarily with minerals, grains, animals, or plants, as indicated by the following examples:

  • 26 September was called Cheval (Horse)
  • 25 October was called Betterave (Beetroot)
  • 27 November was called Chou-fleur (Cauliflower)
  • 7 January was called Pierre à chaux (Limestone)
  • 4 February was called Buis (Box Tree)
  • 12 March was called Persil (Parsley)
  • 13 April was called Roquette (Arugula or Rocket)
  • 14 May was called Carpe (Carp)
  • 4 June was called OEillet (Carnation)
  • 7 July was called Cerise (Cherry)
  • 24 August was called Sucrion (Winter Barley)

Besides the changes to the days, the French Republican calendar was divided into ten hours, each hour into 100 decimal minutes, and each decimal minute into 100 decimal seconds, so that an hour was more than double a conventional hour, to be exact, 144 conventional minutes. To keep track of this new time, special clocks and watches were manufactured.

A Republican Calendar pocket watch showing ten-day décade names and thirty-day month numbers, but with duodecimal time. Courtesy of Wikipedia.

The time change proved unpopular partly because it was complicated and partly because the rest of the world used a different time. Thus, it was officially suspended on 7 April 1795.

It took a while longer for the calendar to be left by the wayside, but about a year and half after Napoleon Bonaparte declared himself Emperor the French Republican calendar was abandoned on 31st of December 1805. The French then returned to using the Gregorian calendar on 1 January 1806. There were various reasons for doing away with the Republican calendar. First, the calendar was never that popular and it was difficult and impractical to have a calendar that was different from the rest of the world, as it constantly required conversions. A second reason was that French workers did not like the 10-day week. Thirdly, one of the main reasons that the Republican calendar was adopted was because of opposition to the Catholic church, which by the early 1800s had waned.

The Cumberland Pacquet, and Ware’s Whitehaven Advertiser reported on the calendar’s demise stating:

“The restoration of the Gregorian Calendar, which by a simple, brief Senatus Consultum, is to recommence with the beginning of the ensuing year, ought not to be passed over merely as the necessary or probable obliteration of one of the follies of a Revolution of folly and crime. It should rather be looked at as a sign of the unpopularity and disgrace of those principles and hopes which gave birth support to the system. The truth is, that the revolutionary calendar was a adopted as one great means for the overthrow of what has been held sacred by the nations of Christendom, and is most dear to its civil, political, and religious interests.

Three classes of men, especially, contemplated its permanent establishment with the most vivid satisfaction; and if they had not all precisely the same reasons for it, the end produced by all of them was nearly the same. The vanity of the scientific men led them to reject the old established mode of computing time, even at the risk and hazard of all its unavoidable difficulties and disadvantages.”[4]

A Dutch newspaper provided this:

“We are again informed, that the present French Calendar will soon be abolished, it being found productive of endless inconvenience in mercantile transactions, in comparing dates of letters and bills of exchange, and possessing not one advantage in return, as it was not even astronomically just, and actually separated us from all the rest of Europe.”[5]


  • [1] Chester Courant, “Democratic Principles Illustrated,” June 26, 1798, p. 4.
  • [2] J. J. Bond, Handy-book of Rules and Tables for Verifying Dates with the Christian Era: Giving an Account of the Chief Eras, and Systems Used by Various Nations, &c, &c (London: G. Bell & Sons, 1889), p. 102.
  • [3] Ibid.
  • [4] Cumberland Pacquet, and Ware’s Whitehaven Advertiser, “The French Calendar,” October 8, 1805, p. 3.
  • [5] Public Ledger and Daily Advertiser,  “From Dutch Papers,” August 9, 1805, p. 2.

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