# French Republican calendar

The French Republican calendar (French: calendrier républicain français), also commonly called the French Revolutionary calendar (calendrier révolutionnaire français), was a calendar created and implemented during the French Revolution and used by the French government for about 12 years from late 1793 to 1805, and for 18 days by the Paris Commune in 1871, meant to replace the Gregorian calendar. The calendar consisted of twelve 30-day months, each divided into three 10-day cycles similar to weeks, plus five or six intercalary days at the end to fill out the balance of a solar year. It was designed in part to remove all religious and royalist influences from the calendar, and it was part of a larger attempt at dechristianisation and decimalisation in France (which also included decimal time of day, decimalisation of currency, and metrication). It was used in government records in France and other areas under French rule, including Belgium, Luxembourg, and parts of the Netherlands, Germany, Switzerland, Malta, and Italy.

## History

The National Constituent Assembly at first intended to create a new calendar marking the "era of Liberty", beginning on 14 July 1789, the date of the storming of the Bastille. However, on 2 January 1792 its successor the Legislative Assembly decided that Year IV of Liberty had begun the day before. Year I had therefore begun on 1 January 1789.
On 21 September 1792 the French First Republic was proclaimed, and the new National Convention decided that 1792 was to be known as Year I of the French Republic. It decreed on 2 January 1793 that Year II of the Republic had begun the day before. However, the new calendar as adopted by the Convention in October 1793 made 22 September 1792 the first day of Year I. The Common Era, commemorating the birth of Jesus Christ, was abolished and replaced with l'ère républicaine, the Republican Era, signifying the "age of reason" overcoming superstition, as part of the campaign of dechristianisation.
The calendar is frequently named the "French Revolutionary Calendar" because it was created during the revolution, but this is a slight misnomer. In France, it is known as the calendrier républicain as well as the calendrier révolutionnaire. There was initially a debate as to whether the calendar should celebrate the revolution, which began in July 1789, or the Republic, which was established in 1792. Immediately following 14 July 1789, papers and pamphlets started calling 1789 year I of Liberty and the following years II and III. It was in 1792, with the practical problem of dating financial transactions, that the legislative assembly was confronted with the problem of the calendar. Originally, the choice of epoch was either 1 January 1789 or 14 July 1789. After some hesitation the assembly decided on 2 January 1792 that all official documents would use the "era of Liberty" and that the year IV of Liberty started on 1 January 1792. This usage was modified on 22 September 1792 when the Republic was proclaimed and the Convention decided that all public documents would be dated Year I of the French Republic. The decree of 2 January 1793 stipulated that the year II of the Republic began on 1 January 1793; this was revoked with the introduction of the calendar, which set 22 September 1793 as the beginning of year II. The establishment of the Republic was used as the epochal date for the calendar; therefore, the calendar commemorates the Republic, and not the Revolution.
The Concordat of 1801 re-established the Roman Catholic Church as an official institution in France, although not as the state religion of France. The concordat took effect from Easter Sunday, 28 Germinal, Year XI (8 April 1802); it restored the names of the days of the week to the ones from the Gregorian calendar, and fixed Sunday as the official day of rest and religious celebration. However, the other attributes of the republican calendar, the months, and years, remained as they were.
The First Republic ended with the coronation of Napoleon I as emperor on 11 Frimaire, Year XIII, or 2 December 1804. Despite this, the republican calendar continued to be used until 1 January 1806, when Napoleon declared it abolished. It was 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).

## Overview and origins
### Precursor

The prominent atheist essayist and philosopher Sylvain Maréchal published the first edition of his Almanach des Honnêtes-gens (Almanac of Honest People) in 1788. The first month in the almanac is "Mars, ou Princeps" (March, or First), the last month is "Février, ou Duodécembre" (February, or Twelfth). The lengths of the months are the same as those in the Gregorian calendar; however, the 10th, 20th, and 30th days are singled out of each month as the end of a décade (group of ten days). Individual days were assigned, instead of to the traditional saints, to people noteworthy for mostly secular achievements. Later editions of the almanac would switch to the Republican Calendar.

### Development and usage

The days of the French Revolution and First French Republic saw many efforts to sweep away various trappings of the ancien régime (the old feudal monarchy); some of these were more successful than others. The new Republican government sought to institute, among other reforms, a new social and legal system, a new system of weights and measures (which became the metric system), and a new calendar.
Amid nostalgia for the ancient Roman Republic, the theories of the Age of Enlightenment were at their peak, and the devisers of the new systems looked to nature for their inspiration. Natural constants, multiples of ten, and Latin as well as Ancient Greek derivations formed the fundamental blocks from which the systems were built.
The calendar was created by a commission under the direction of the politician Gilbert Romme seconded by Claude Joseph Ferry [fr] and Charles-François Dupuis. They associated with their work chemist Louis-Bernard Guyton de Morveau, mathematician and astronomer Joseph-Louis Lagrange, astronomer Jérôme Lalande, mathematician Gaspard Monge, astronomer and naval geographer Alexandre Guy Pingré, and poet, actor and playwright Fabre d'Églantine (who invented the names of the months) with the help of André Thouin (gardener at the Jardin des plantes of the Muséum National d'Histoire Naturelle in Paris). As the rapporteur of the commission, Romme presented the 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 is because of his position as rapporteur of the commission that the creation of the republican calendar is attributed to Romme.
French coins of the period used the calendar. Many show the year (French: an) in Arabic numerals, although Roman numerals were used on some issues. Year 11 coins typically have a "XI" date to avoid confusion with the Roman "II".

## Design

Years appear in writing as Roman numerals (usually). Roman numeral I indicates the first year of the republic, that is, the year before the calendar actually came into use. By law, the beginning of each year was set at midnight, beginning on the day the apparent autumnal equinox falls at the Paris Observatory.
There were twelve months, each divided into three 10-day weeks called décades. The tenth day, décadi, replaced Sunday as the day of rest and festivity. The five or six extra days needed to approximate the solar or tropical year were placed after the final month of each year and called complementary days. This arrangement was an almost exact copy of the calendar used by the Ancient Egyptians, though in their case the year did not begin and end on the autumnal equinox.
A period of four years ending on a leap day was to be called a "Franciade". The name "Olympique" was originally proposed but changed to Franciade to commemorate the fact that it had taken the revolution four years to establish a republican government in France. The leap year was called Sextile, an allusion to the "bissextile" leap years of the Julian and Gregorian calendars, because it contained a sixth complementary day.
Each day was divided into ten hours, each hour into 100 decimal minutes, and each decimal minute into 100 decimal seconds. Thus an hour was 144 conventional minutes (2.4 times as long as a conventional hour), a minute was 86.4 conventional seconds (44% longer than a conventional minute), and a second was 0.864 conventional seconds (13.6% shorter than a conventional second). Clocks were manufactured to display this decimal time, but it did not catch on. Mandatory use of decimal time was officially suspended 7 April 1795, although some cities continued to use decimal time as late as 1801. The numbering of years by Roman numerals ran counter to this general decimalisation tendency.

### Months

The month names were based on nature, principally having to do with the prevailing weather in and around Paris and sometimes evoking the Medieval Labours of the Months. The extra five or six days in the year were not given a month designation but considered Sansculottides or complementary days. Most of the month names were new words coined from French, Latin, or Greek. The endings of the names were grouped by season. -dor comes from δῶρον, dō̂ron means 'giving' in Greek.
* Autumn:
** Vendémiaire (from French vendange, which means 'grape harvest', derived from Latin vindemia 'vintage'), starting 22, 23, or 24 September
** Brumaire (from French brume 'mist', from Latin brūma 'winter solstice; winter; winter cold'), starting 22, 23, or 24 October
** Frimaire (from French frimas 'frost'), starting 21, 22, or 23 November
* Winter:
** Nivôse (from Latin nivosus 'snowy'), starting 21, 22, or 23 December
** Pluviôse (from French pluvieux, derived from Latin pluvius 'rainy'), starting 20, 21, or 22 January
** Ventôse (from French venteux, derived from Latin ventosus 'windy'), starting 19, 20, or 21 February
* Spring:
** Germinal (from French germination), starting 21 or 22 March
** Floréal (from French fleur, derived from Latin flos 'flower'), starting 20 or 21 April
** Prairial (from French prairie 'meadow'), starting 20 or 21 May
* Summer:
** Messidor (from Latin messis 'harvest'), starting 19 or 20 June
** Thermidor (from Greek θέρμη, thermē, 'summer heat'), starting 19 or 20 July; on many printed calendars of Year II (1793–94), the month of Thermidor was named Fervidor (from Latin fervidus, "burning hot")
** Fructidor (from Latin fructus 'fruit'), starting 18 or 19 August
In Britain, a contemporary wit mocked the calendar by calling the months: Wheezy, Sneezy, and Freezy; Slippy, Drippy, and Nippy; Showery, Flowery, and Bowery; Hoppy, Croppy, and Poppy. Historian Thomas Carlyle suggests somewhat more serious English names in his 1837 work The French Revolution: A History, namely Vintagearious, Fogarious, Frostarious, Snowous, Rainous, Windous, Buddal, Floweral, Meadowal, Reapidor, Heatidor, and Fruitidor. Like the French originals, they are neologisms suggesting a meaning related to the season.

### Days

Each month was divided into three décades or "weeks" of ten days each, named:
* 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)
* décadi (tenth day)
Décadis became an official day of rest instead of Sunday, in order to diminish the influence of the Roman Catholic Church. They were used for the festivals of a succession of new religions meant to replace Catholicism: the Cult of Reason, the Cult of the Supreme Being, the Decadary Cult, and Theophilanthropy. Christian holidays were officially abolished in favor of revolutionary holidays. The law of 13 Fructidor year VI (August 30, 1798) required that marriages must only be celebrated on décadis. This law was applied from the 1st Vendémiaire year VII (September 22, 1798) to 28 Pluviôse year VIII (February 17, 1800).
Five extra days – six in leap years – were national holidays at the end of every year. These were originally known as les sans-culottides (after sans-culottes), but after year III (1795) as les jours complémentaires:
* 1st complementary day: La Fête de la Vertu, "Celebration of Virtue", on 17 or 18 September
* 2nd complementary day: La Fête du Génie, "Celebration of Talent", on 18 or 19 September
* 3rd complementary day: La Fête du Travail, "Celebration of Labour", on 19 or 20 September
* 4th complementary day: La Fête de l'Opinion, "Celebration of Convictions", on 20 or 21 September
* 5th complementary day: La Fête des Récompenses, "Celebration of Honours (Awards)", on 21 or 22 September
* 6th complementary day: La Fête de la Révolution, "Celebration of the Revolution", on 22 or 23 September (on leap years only)

### Rural calendar

The Roman Catholic Church used a calendar of saints, which named each day of the year after an associated saint. To reduce the influence of the Church, Fabre d'Églantine introduced a rural calendar in which each day of the year had a unique name associated with the rural economy, stated to correspond to the time of year. Every décadi (ending in 0) was named after an agricultural tool. Each quintidi (ending in 5) was named for a common animal. The rest of the days were named for "grain, pasture, trees, roots, flowers, fruits" and other plants, except for the first month of winter, Nivôse, during which the rest of the days were named after minerals.
   Our starting point was the idea of celebrating, through the calendar, the agricultural system, and of leading the nation back to it, marking the times and the fractions of the year by intelligible or visible signs taken from agriculture and the rural economy. (...)
   As the calendar is something that we use so often, we must take advantage of this frequency of use to put elementary notions of agriculture before the people – to show the richness of nature, to make them love the fields, and to methodically show them the order of the influences of the heavens and of the products of the earth.
   The priests assigned the commemoration of a so-called saint to each day of the year: this catalogue exhibited neither utility nor method; it was a collection of lies, of deceit or of charlatanism.
   We thought that the nation, after having kicked out this canonised mob from its calendar, must replace it with the objects that make up the true riches of the nation, worthy objects not from a cult, but from agriculture – useful products of the soil, the tools that we use to cultivate it, and the domesticated animals, our faithful servants in these works; animals much more precious, without doubt, to the eye of reason, than the beatified skeletons pulled from the catacombs of Rome.
   So we have arranged in the column of each month, the names of the real treasures of the rural economy. The grains, the pastures, the trees, the roots, the flowers, the fruits, the plants are arranged in the calendar, in such a way that the place and the day of the month that each product occupies is precisely the season and the day that Nature presents it to us.

## Criticism and shortcomings

Leap years in the calendar are a point of great dispute, due to the contradicting statements in the establishing decree stating:
   Each year begins at midnight, with the day on which the true autumnal equinox falls for the Paris Observatory.
and:
   The four-year period, after which the addition of a day is usually necessary, is called the Franciade in memory of the revolution which, after four years of effort, led France to republican government. The fourth year of the Franciade is called Sextile.
These two specifications are incompatible, as leap years defined by the autumnal equinox in Paris do not recur on a regular four-year schedule. It was erroneously believed that one leap day would be skipped automatically every 129 years, on average, but actually five years would sometimes pass between leap years, about three times per century. Thus, the years III, VII, and XI were observed as leap years, and the years XV and XX were also planned as such, even though they were five years apart.
A fixed arithmetic rule for determining leap years was proposed by Delambre and presented to the Committee of Public Education by Romme on 19 Floréal An III (8 May 1795). The proposed rule was to determine leap years by applying the rules of the Gregorian calendar to the years of the French Republic (years IV, VIII, XII, etc. were to be leap years) except that year 4000 (the last year of ten 400-year periods) should be a common year instead of a leap year. Shortly thereafter, Romme was sentenced to the guillotine and committed suicide, and the proposal was never adopted, although Jérôme Lalande repeatedly proposed it for a number of years. The proposal was intended to avoid uncertain future leap years caused by the inaccurate astronomical knowledge of the 1790s (even today, this statement is still valid due to the uncertainty in ΔT). In particular, the committee noted that the autumnal equinox of year 144 was predicted to occur at 11:59:40 pm local apparent time in Paris, which was closer to midnight than its inherent 3 to 4 minute uncertainty.
The calendar was abolished by an act dated 22 Fructidor an XIII (9 September 1805) and signed by Napoleon, which referred to a report by Michel-Louis-Étienne Regnaud de Saint-Jean d'Angély and Jean Joseph Mounier, listing two fundamental flaws.
* The rule for leap years depended upon the uneven course of the sun, rather than fixed intervals, so that one must consult astronomers to determine when each year started, especially when the equinox happened close to midnight, as the exact moment could not be predicted with certainty.
* Both the era and the beginning of the year were chosen to commemorate a historical event that occurred on the first day of autumn in France, whereas the other European nations began the year near the beginning of winter or spring, thus being impediments to the calendar's adoption in Europe and America, and even a part of the French nation, where the Gregorian calendar continued to be used, as it was required for religious purposes.
The report also notes that the 10-day décade was unpopular and had already been suppressed three years earlier in favor of the seven-day week, removing what was considered by some as one of the calendar's main benefits. The 10-day décade was unpopular with laborers because they received only one full day of rest out of ten, instead of one in seven, although they also got a half-day off on the fifth day (thus 36 full days and 36 half days in a year, for a total of 54 free days, compared to the usual 52 or 53 Sundays). It also, by design, conflicted with Sunday religious observances.
Another criticism of the calendar was that despite the poetic names of its months, they were tied to the climate and agriculture of metropolitan France and therefore not applicable to France's overseas territories.

## Gallery

The following pictures, showing twelve allegories for the months, were illustrated by French painter Louis Lafitte and engraved by Salvatore Tresca [fr].

### Autumn

Vendémiaire (22/24 September – 21/23 October) :
| 1 | 22 Sep | Raisin (Grape) |
| 2 | 23 Sep | Safran (Saffron) |
| 3 | 24 Sep | Châtaigne (Chestnut) |
| 4 | 25 Sep | Colchique (Autumn Crocus) |
| 5 | 26 Sep | Cheval (Horse) |
| 6 | 27 Sep | Balsamine (Impatiens) |
| 7 | 28 Sep | Carotte (Carrot) |
| 8 | 29 Sep | Amaranthe (Amaranth) |
| 9 | 30 Sep | Panais (Parsnip) |
| 10 | 1 Oct | Cuve (Vat) |
| 11 | 2 Oct | Pomme de terre (Potato) |
| 12 | 3 Oct | Immortelle (Strawflower) |
| 13 | 4 Oct | Potiron (Winter squash) |
| 14 | 5 Oct | Réséda (Mignonette) |
| 15 | 6 Oct | Âne (Donkey) |
| 16 | 7 Oct | Belle de nuit (Four o'clock flower) |
| 17 | 8 Oct | Citrouille (Pumpkin) |
| 18 | 9 Oct | Sarrasin (Buckwheat) |
| 19 | 10 Oct | Tournesol (Sunflower) |
| 20 | 11 Oct | Pressoir (Wine-Press) |
| 21 | 12 Oct | Chanvre (Hemp) |
| 22 | 13 Oct | Pêche (Peach) |
| 23 | 14 Oct | Navet (Turnip) |
| 24 | 15 Oct | Amaryllis (Amaryllis) |
| 25 | 16 Oct | Bœuf (Ox) |
| 26 | 17 Oct | Aubergine (Eggplant) |
| 27 | 18 Oct | Piment (Chili pepper) |
| 28 | 19 Oct | Tomate (Tomato) |
| 29 | 20 Oct | Orge (Barley) |
| 30 | 21 Oct | Tonneau (Barrel) |
Brumaire (22/24 October – 20/22 November) :
| 1 | 22 Oct | Pomme (Apple) |
| 2 | 23 Oct | Céleri (Celery) |
| 3 | 24 Oct | Poire (Pear) |
| 4 | 25 Oct | Betterave (Beetroot) |
| 5 | 26 Oct | Oie (Goose) |
| 6 | 27 Oct | Héliotrope (Heliotrope) |
| 7 | 28 Oct | Figue (Common fig) |
| 8 | 29 Oct | Scorsonère (Black Salsify) |
| 9 | 30 Oct | Alisier (Chequer Tree) |
| 10 | 31 Oct | Charrue (Plough) |
| 11 | 1 Nov | Salsifis (Salsify) |
| 12 | 2 Nov | Mâcre (Water caltrop) |
| 13 | 3 Nov | Topinambour (Jerusalem artichoke) |
| 14 | 4 Nov | Endive (Endive) |
| 15 | 5 Nov | Dindon (Turkey) |
| 16 | 6 Nov | Chervis (Skirret) |
| 17 | 7 Nov | Cresson (Watercress) |
| 18 | 8 Nov | Dentelaire (Leadworts) |
| 19 | 9 Nov | Grenade (Pomegranate) |
| 20 | 10 Nov | Herse (Harrow) |
| 21 | 11 Nov | Bacchante (Baccharis) |
| 22 | 12 Nov | Azerole (Azarole) |
| 23 | 13 Nov | Garance (Madder) |
| 24 | 14 Nov | Orange (Orange) |
| 25 | 15 Nov | Faisan (Pheasant) |
| 26 | 16 Nov | Pistache (Pistachio Nut) |
| 27 | 17 Nov | Macjonc (Tuberous pea) |
| 28 | 18 Nov | Coing (Quince) |
| 29 | 19 Nov | Cormier (Service tree) |
| 30 | 20 Nov | Rouleau (Roller) |
Frimaire (21/23 November – 20/22 December) :
| 1 | 21 Nov | Raiponce (Rampion) |
| 2 | 22 Nov | Turneps (Cattle turnip) |
| 3 | 23 Nov | Chicorée (Chicory) |
| 4 | 24 Nov | Nèfle (Medlar) |
| 5 | 25 Nov | Cochon (Pig) |
| 6 | 26 Nov | Mâche (Lamb's lettuce) |
| 7 | 27 Nov | Chou-fleur (Cauliflower) |
| 8 | 28 Nov | Miel (Honey) |
| 9 | 29 Nov | Genièvre (Juniper) |
| 10 | 30 Nov | Pioche (Pickaxe) |
| 11 | 1 Dec | Cire (Wax) |
| 12 | 2 Dec | Raifort (Horseradish) |
| 13 | 3 Dec | Cèdre (Cedar tree) |
| 14 | 4 Dec | Sapin (Fir) |
| 15 | 5 Dec | Chevreuil (Roe deer) |
| 16 | 6 Dec | Ajonc (Gorse) |
| 17 | 7 Dec | Cyprès (Cypress Tree) |
| 18 | 8 Dec | Lierre (Ivy) |
| 19 | 9 Dec | Sabine (Savin Juniper) |
| 20 | 10 Dec | Hoyau (Fork hoe) |
| 21 | 11 Dec | Érable à sucre (Sugar Maple) |
| 22 | 12 Dec | Bruyère (Heather) |
| 23 | 13 Dec | Roseau (Reed plant) |
| 24 | 14 Dec | Oseille (Sorrel) |
| 25 | 15 Dec | Grillon (Cricket) |
| 26 | 16 Dec | Pignon (Pine nut) |
| 27 | 17 Dec | Liège (Cork) |
| 28 | 18 Dec | Truffe (Truffle) |
| 29 | 19 Dec | Olive (Olive) |
| 30 | 20 Dec | Pelle (Shovel) |

### Winter

Nivôse (21/23 December – 19/21 January) :
| 1 | 21 Dec | Tourbe (Peat) |
| 2 | 22 Dec | Houille (Coal) |
| 3 | 23 Dec | Bitume (Bitumen) |
| 4 | 24 Dec | Soufre (Sulphur) |
| 5 | 25 Dec | Chien (Dog) |
| 6 | 26 Dec | Lave (Lava) |
| 7 | 27 Dec | Terre végétale (Topsoil) |
| 8 | 28 Dec | Fumier (Manure) |
| 9 | 29 Dec | Salpêtre (Saltpeter) |
| 10 | 30 Dec | Fléau (Flail) |
| 11 | 31 Dec | Granit (Granite) |
| 12 | 1 Jan | Argile (Clay) |
| 13 | 2 Jan | Ardoise (Slate) |
| 14 | 3 Jan | Grès (Sandstone) |
| 15 | 4 Jan | Lapin (Rabbit) |
| 16 | 5 Jan | Silex (Flint) |
| 17 | 6 Jan | Marne (Marl) |
| 18 | 7 Jan | Pierre à chaux (Limestone) |
| 19 | 8 Jan | Marbre (Marble) |
| 20 | 9 Jan | Van (Winnowing fan) |
| 21 | 10 Jan | Pierre à plâtre (Gypsum) |
| 22 | 11 Jan | Sel (Salt) |
| 23 | 12 Jan | Fer (Iron) |
| 24 | 13 Jan | Cuivre (Copper) |
| 25 | 14 Jan | Chat (Cat) |
| 26 | 15 Jan | Étain (Tin) |
| 27 | 16 Jan | Plomb (Lead) |
| 28 | 17 Jan | Zinc (Zinc) |
| 29 | 18 Jan | Mercure (Mercury) |
| 30 | 19 Jan | Crible (Sieve) |
Pluviôse (20/22 January – 18/20 February) :
| 1 | 20 Jan | Lauréole (Spurge-laurel) |
| 2 | 21 Jan | Mousse (Moss) |
| 3 | 22 Jan | Fragon (Butcher's Broom) |
| 4 | 23 Jan | Perce-neige (Snowdrop) |
| 5 | 24 Jan | Taureau (Bull) |
| 6 | 25 Jan | Laurier-thym (Laurustinus) |
| 7 | 26 Jan | Amadouvier (Tinder polypore) |
| 8 | 27 Jan | Mézéréon (Daphne mezereum) |
| 9 | 28 Jan | Peuplier (Poplar) |
| 10 | 29 Jan | Coignée (Axe) |
| 11 | 30 Jan | Ellébore (Hellebore) |
| 12 | 31 Jan | Brocoli (Broccoli) |
| 13 | 1 Feb | Laurier (Bay laurel) |
| 14 | 2 Feb | Avelinier (Filbert) |
| 15 | 3 Feb | Vache (Cow) |
| 16 | 4 Feb | Buis (Box Tree) |
| 17 | 5 Feb | Lichen (Lichen) |
| 18 | 6 Feb | If (Yew tree) |
| 19 | 7 Feb | Pulmonaire (Lungwort) |
| 20 | 8 Feb | Serpette (Billhook) |
| 21 | 9 Feb | Thlaspi (Pennycress) |
| 22 | 10 Feb | Thimelé (Rose Daphne) |
| 23 | 11 Feb | Chiendent (Couch grass) |
| 24 | 12 Feb | Trainasse (Common Knotgrass) |
| 25 | 13 Feb | Lièvre (Hare) |
| 26 | 14 Feb | Guède (Woad) |
| 27 | 15 Feb | Noisetier (Hazel) |
| 28 | 16 Feb | Cyclamen (Cyclamen) |
| 29 | 17 Feb | Chélidoine (Celandine) |
| 30 | 18 Feb | Traîneau (Sleigh) |
Ventôse (19/21 February – 20/22 March) :
| 1 | 19 Feb | Tussilage (Coltsfoot) |
| 2 | 20 Feb | Cornouiller (Dogwood) |
| 3 | 21 Feb | Violier (Matthiola) |
| 4 | 22 Feb | Troène (Privet) |
| 5 | 23 Feb | Bouc (Billygoat) |
| 6 | 24 Feb | Asaret (Wild Ginger) |
| 7 | 25 Feb | Alaterne (Italian Buckthorn) |
| 8 | 26 Feb | Violette (Violet) |
| 9 | 27 Feb | Marceau (Goat Willow) |
| 10 | 28 Feb | Bêche (Spade) |
| 11 | 1 Mar | Narcisse (Narcissus) |
| 12 | 2 Mar | Orme (Elm) |
| 13 | 3 Mar | Fumeterre (Common fumitory) |
| 14 | 4 Mar | Vélar (Hedge mustard) |
| 15 | 5 Mar | Chèvre (Goat) |
| 16 | 6 Mar | Épinard (Spinach) |
| 17 | 7 Mar | Doronic (Doronicum) |
| 18 | 8 Mar | Mouron (Pimpernel) |
| 19 | 9 Mar | Cerfeuil (Chervil) |
| 20 | 10 Mar | Cordeau (Twine) |
| 21 | 11 Mar | Mandragore (Mandrake) |
| 22 | 12 Mar | Persil (Parsley) |
| 23 | 13 Mar | Cochléaria (Scurvy-grass) |
| 24 | 14 Mar | Pâquerette (Daisy) |
| 25 | 15 Mar | Thon (Tuna) |
| 26 | 16 Mar | Pissenlit (Dandelion) |
| 27 | 17 Mar | Sylvie (Wood Anemone) |
| 28 | 18 Mar | Capillaire (Maidenhair fern) |
| 29 | 19 Mar | Frêne (Ash tree) |
| 30 | 20 Mar | Plantoir (Dibber) |

### Spring

Germinal (21/23 March – 19/21 April) :
| 1 | 21 Mar | Primevère (Primrose) |
| 2 | 22 Mar | Platane (Plane Tree) |
| 3 | 23 Mar | Asperge (Asparagus) |
| 4 | 24 Mar | Tulipe (Tulip) |
| 5 | 25 Mar | Poule (Hen) |
| 6 | 26 Mar | Bette (Chard) |
| 7 | 27 Mar | Bouleau (Birch) |
| 8 | 28 Mar | Jonquille (Daffodil) |
| 9 | 29 Mar | Aulne (Alder) |
| 10 | 30 Mar | Couvoir (Incubator) |
| 11 | 31 Mar | Pervenche (Periwinkle) |
| 12 | 1 Apr | Charme (Hornbeam) |
| 13 | 2 Apr | Morille (Morel) |
| 14 | 3 Apr | Hêtre (Beech Tree) |
| 15 | 4 Apr | Abeille (Bee) |
| 16 | 5 Apr | Laitue (Lettuce) |
| 17 | 6 Apr | Mélèze (Larch) |
| 18 | 7 Apr | Ciguë (Hemlock) |
| 19 | 8 Apr | Radis (Radish) |
| 20 | 9 Apr | Ruche (Beehive) |
| 21 | 10 Apr | Gainier (Judas tree) |
| 22 | 11 Apr | Romaine (Romaine lettuce) |
| 23 | 12 Apr | Marronnier (Horse chestnut) |
| 24 | 13 Apr | Roquette (Arugula or Rocket) |
| 25 | 14 Apr | Pigeon (Pigeon) |
| 26 | 15 Apr | Lilas (Lilac) |
| 27 | 16 Apr | Anémone (Anemone) |
| 28 | 17 Apr | Pensée (Pansy) |
| 29 | 18 Apr | Myrtille (Bilberry) |
| 30 | 19 Apr | Greffoir (Grafting knife) |
Floréal (20/22 April – 19/21 May) :
| 1 | 20 Apr | Rose (Rose) |
| 2 | 21 Apr | Chêne (Oak Tree) |
| 3 | 22 Apr | Fougère (Fern) |
| 4 | 23 Apr | Aubépine (Hawthorn) |
| 5 | 24 Apr | Rossignol (Nightingale) |
| 6 | 25 Apr | Ancolie (Common Columbine) |
| 7 | 26 Apr | Muguet (Lily of the valley) |
| 8 | 27 Apr | Champignon (Button mushroom) |
| 9 | 28 Apr | Hyacinthe (Hyacinth) |
| 10 | 29 Apr | Râteau (Rake) |
| 11 | 30 Apr | Rhubarbe (Rhubarb) |
| 12 | 1 May | Sainfoin (Sainfoin) |
| 13 | 2 May | Bâton d'or (Wallflower) |
| 14 | 3 May | Chamerisier (Fan Palm tree) |
| 15 | 4 May | Ver à soie (Silkworm) |
| 16 | 5 May | Consoude (Comfrey) |
| 17 | 6 May | Pimprenelle (Salad burnet) |
| 18 | 7 May | Corbeille d'or (Basket of Gold) |
| 19 | 8 May | Arroche (Orache) |
| 20 | 9 May | Sarcloir (Weeding hoe) |
| 21 | 10 May | Statice (Sea thrift) |
| 22 | 11 May | Fritillaire (Fritillary) |
| 23 | 12 May | Bourrache (Borage) |
| 24 | 13 May | Valériane (Valerian) |
| 25 | 14 May | Carpe (Carp) |
| 26 | 15 May | Fusain (Euonymus) |
| 27 | 16 May | Civette (Chives) |
| 28 | 17 May | Buglosse (Bugloss) |
| 29 | 18 May | Sénevé (White mustard) |
| 30 | 19 May | Houlette (Shepherd's crook) |
Prairial (20/22 May – 18/20 June) :
| 1 | 20 May | Luzerne (Lucerne) |
| 2 | 21 May | Hémérocalle (Daylily) |
| 3 | 22 May | Trèfle (Clover) |
| 4 | 23 May | Angélique (Angelica) |
| 5 | 24 May | Canard (Duck) |
| 6 | 25 May | Mélisse (Lemon balm) |
| 7 | 26 May | Fromental (Oat grass) |
| 8 | 27 May | Martagon (Martagon lily) |
| 9 | 28 May | Serpolet (Wild Thyme) |
| 10 | 29 May | Faux (Scythe) |
| 11 | 30 May | Fraise (Strawberry) |
| 12 | 31 May | Bétoine (Betony) |
| 13 | 1 Jun | Pois (Pea) |
| 14 | 2 Jun | Acacia (Acacia) |
| 15 | 3 Jun | Caille (Quail) |
| 16 | 4 Jun | Œillet (Carnation) |
| 17 | 5 Jun | Sureau (Elderberry) |
| 18 | 6 Jun | Pavot (Poppy plant) |
| 19 | 7 Jun | Tilleul (Linden or Lime tree) |
| 20 | 8 Jun | Fourche (Pitchfork) |
| 21 | 9 Jun | Barbeau (Cornflower) |
| 22 | 10 Jun | Camomille (Camomile) |
| 23 | 11 Jun | Chèvrefeuille (Honeysuckle) |
| 24 | 12 Jun | Caille-lait (Bedstraw) |
| 25 | 13 Jun | Tanche (Tench) |
| 26 | 14 Jun | Jasmin (Jasmine) |
| 27 | 15 Jun | Verveine (Vervain) |
| 28 | 16 Jun | Thym (Thyme) |
| 29 | 17 Jun | Pivoine (Peony) |
| 30 | 18 Jun | Chariot (Handcart) |

### Summer

Messidor (19/21 June – 18/20 July) :
| 1 | 19 Jun | Seigle (Rye) |
| 2 | 20 Jun | Avoine (Oat) |
| 3 | 21 Jun | Oignon (Onion) |
| 4 | 22 Jun | Véronique (Speedwell) |
| 5 | 23 Jun | Mulet (Mule) |
| 6 | 24 Jun | Romarin (Rosemary) |
| 7 | 25 Jun | Concombre (Cucumber) |
| 8 | 26 Jun | Échalote (Shallot) |
| 9 | 27 Jun | Absinthe (Wormwood) |
| 10 | 28 Jun | Faucille (Sickle) |
| 11 | 29 Jun | Coriandre (Coriander) |
| 12 | 30 Jun | Artichaut (Artichoke) |
| 13 | 1 Jul | Girofle (Clove) |
| 14 | 2 Jul | Lavande (Lavender) |
| 15 | 3 Jul | Chamois (Chamois) |
| 16 | 4 Jul | Tabac (Tobacco) |
| 17 | 5 Jul | Groseille (Redcurrant) |
| 18 | 6 Jul | Gesse (Hairy Vetchling) |
| 19 | 7 Jul | Cerise (Cherry) |
| 20 | 8 Jul | Parc (Livestock pen) |
| 21 | 9 Jul | Menthe (Mint) |
| 22 | 10 Jul | Cumin (Cumin) |
| 23 | 11 Jul | Haricot (Bean) |
| 24 | 12 Jul | Orcanète (Alkanet) |
| 25 | 13 Jul | Pintade (Guineafowl) |
| 26 | 14 Jul | Sauge (Sage) |
| 27 | 15 Jul | Ail (Garlic) |
| 28 | 16 Jul | Vesce (Tare) |
| 29 | 17 Jul | Blé (Wheat) |
| 30 | 18 Jul | Chalémie (Shawm) |
Thermidor (19/21 July – 17/19 August) :
| 1 | 19 Jul | Épeautre (Spelt) |
| 2 | 20 Jul | Bouillon blanc (Common mullein) |
| 3 | 21 Jul | Melon (Melon) |
| 4 | 22 Jul | Ivraie (Ryegrass) |
| 5 | 23 Jul | Bélier (Ram) |
| 6 | 24 Jul | Prêle (Horsetail) |
| 7 | 25 Jul | Armoise (Mugwort) |
| 8 | 26 Jul | Carthame (Safflower) |
| 9 | 27 Jul | Mûre (Blackberry) |
| 10 | 28 Jul | Arrosoir (Watering can) |
| 11 | 29 Jul | Panic (Foxtail millet) |
| 12 | 30 Jul | Salicorne (Common Glasswort) |
| 13 | 31 Jul | Abricot (Apricot) |
| 14 | 1 Aug | Basilic (Basil) |
| 15 | 2 Aug | Brebis (Ewe) |
| 16 | 3 Aug | Guimauve (Marshmallow) |
| 17 | 4 Aug | Lin (Flax) |
| 18 | 5 Aug | Amande (Almond) |
| 19 | 6 Aug | Gentiane (Gentian) |
| 20 | 7 Aug | Écluse (Lock) |
| 21 | 8 Aug | Carline (Carline thistle) |
| 22 | 9 Aug | Câprier (Caper) |
| 23 | 10 Aug | Lentille (Lentil) |
| 24 | 11 Aug | Aunée (Inula) |
| 25 | 12 Aug | Loutre (Otter) |
| 26 | 13 Aug | Myrte (Myrtle) |
| 27 | 14 Aug | Colza (Rapeseed) |
| 28 | 15 Aug | Lupin (Lupin) |
| 29 | 16 Aug | Coton (Cotton) |
| 30 | 17 Aug | Moulin (Mill) |
Fructidor (18/20 August – 16/18 September) :
| 1 | 18 Aug | Prune (Plum) |
| 2 | 19 Aug | Millet (Millet) |
| 3 | 20 Aug | Lycoperdon (Puffball) |
| 4 | 21 Aug | Escourgeon (Six-row Barley) |
| 5 | 22 Aug | Saumon (Salmon) |
| 6 | 23 Aug | Tubéreuse (Tuberose) |
| 7 | 24 Aug | Sucrion (Winter Barley) |
| 8 | 25 Aug | Apocyn (Apocynum) |
| 9 | 26 Aug | Réglisse (Liquorice) |
| 10 | 27 Aug | Échelle (Ladder) |
| 11 | 28 Aug | Pastèque (Watermelon) |
| 12 | 29 Aug | Fenouil (Fennel) |
| 13 | 30 Aug | Épine vinette (European Barberry) |
| 14 | 31 Aug | Noix (Walnut) |
| 15 | 1 Sep | Truite (Trout) |
| 16 | 2 Sep | Citron (Lemon) |
| 17 | 3 Sep | Cardère (Teasel) |
| 18 | 4 Sep | Nerprun (Buckthorn) |
| 19 | 5 Sep | Tagette (Mexican Marigold) |
| 20 | 6 Sep | Hotte (Harvesting basket) |
| 21 | 7 Sep | Églantier (Wild Rose) |
| 22 | 8 Sep | Noisette (Hazelnut) |
| 23 | 9 Sep | Houblon (Hops) |
| 24 | 10 Sep | Sorgho (Sorghum) |
| 25 | 11 Sep | Écrevisse (Crayfish) |
| 26 | 12 Sep | Bigarade (Bitter orange) |
| 27 | 13 Sep | Verge d'or (Goldenrod) |
| 28 | 14 Sep | Maïs (Maize or Corn) |
| 29 | 15 Sep | Marron (Sweet Chestnut) |
| 30 | 16 Sep | Panier (Pack Basket) |

## Conversion to conventional timekeeping
### During the Republic

Below are the Gregorian dates each year of the Republican Era (Ère Républicaine in French) began while the calendar was in effect.
| ER | AD/CE |
| I (1) | 22 September 1792 |
| II (2) | 22 September 1793 |
| III (3) | 22 September 1794 |
| IV (4) | 23 September 1795* |
| V (5) | 22 September 1796 |
| VI (6) | 22 September 1797 |
| VII (7) | 22 September 1798 |
| VIII (8) | 23 September 1799* |
| IX (9) | 23 September 1800 |
| X (10) | 23 September 1801 |
| XI (11) | 23 September 1802 |
| XII (12) | 24 September 1803* |
| XIII (13) | 23 September 1804 |
| XIV (14) | 23 September 1805 |
| LXXIX (79) | 23 September 1870 |
Leap years are highlighted
* Extra (sextile) day inserted before date, due to previous leap year

### After the Republic

The Republican Calendar was abolished in the year XIV (1805). After this year, there are two historically attested calendars which may be used to determine dates. Both calendars gave the same dates for years 17 to 52 (1808–1844), always beginning on 23 September, and it was suggested, but never adopted, that the reformed calendar be implemented during this period, before the Republican Calendar was abolished.
* Republican Calendar: The only legal calendar during the Republic. The first day of the year, 1 Vendémiaire, is always the day the autumn equinox occurs in Paris. About every 30 years, leap years are 5 years apart instead of 4, as happened between the leap years 15 and 20. The lengths of the first 524 years were calculated by Jean Baptiste Joseph Delambre.
* Reformed Republican Calendar: Following a proposal by Delambre in order to make leap years regular and predictable, with leap years being every year divisible by 4, except years divisible by 100 and not by 400. Years divisible by 4000 would also be ordinary years. Intended to be implemented in year 3, the reformed calendar was abandoned after the death of Romme, the head of the calendar committee. This calendar also has the benefit that every year in the third century of the Republican Era (1992–2091) begins on 22 September.
| ER | AD/CE | Republican | Reformed |
| XV (15) | 1806 | 23 September | 23 September |
| XVI (16) | 1807 | 24 September* | 23 September |
| XVII (17) | 1808 | 23 September | 23 September* |
| XVIII (18) | 1809 | 23 September | 23 September |
| XIX (19) | 1810 | 23 September | 23 September |
| XX (20) | 1811 | 23 September | 23 September |
| CCXXIX (229) | 2020 | 22 September | 22 September* |
| CCXXX (230) | 2021 | 22 September | 22 September |
| CCXXXI (231) | 2022 | 23 September* | 22 September |
| CCXXXII (232) | 2023 | 23 September | 22 September |
| CCXXXIII (233) | 2024 | 22 September | 22 September* |
| CCXXXIV (234) | 2025 | 22 September | 22 September |
| CCXXXV (235) | 2026 | 23 September* | 22 September |
| CCXXXVI (236) | 2027 | 23 September | 22 September |
| CCXXXVII (237) | 2028 | 22 September | 22 September* |
| CCXXXVIII (238) | 2029 | 22 September | 22 September |
| CCXXXIX (239) | 2030 | 22 September | 22 September |
| CCXL (240) | 2031 | 23 September* | 22 September |
| CCXLI (241) | 2032 | 22 September | 22 September* |
Leap years are highlighted
* Extra (sextile) day inserted before date, due to previous leap year

### Current date and time

For this calendar, Delambre's revised method of calculating leap years is used. Other methods may differ by one day. Time may be cached and therefore not accurate. Decimal time is according to Paris mean time, which is 9 minutes 21 seconds (6.49 decimal minutes) ahead of Greenwich Mean Time. (This tool calibrates the time, if calibration is desired.)
| Year: 233 | Month: Ventôse | Month: Ventôse | Month: Ventôse | Year: CCXXXIII |
| Day of the 10-day week (décade) Primidi Duodi Tridi Quartidi Quintidi Sextidi Septidi Octidi Nonidi Décadi | décade 16 1 Wednesday 19 February 2025 2 Thursday 20 February 2025 3 Friday 21 February 2025 4 Saturday 22 February 2025 5 Sunday 23 February 2025 6 Monday 24 February 2025 7 Tuesday 25 February 2025 8 Wednesday 26 February 2025 9 Thursday 27 February 2025 10 Friday 28 February 2025 | décade 17 11 Saturday 1 March 2025 12 Sunday 2 March 2025 13 Monday 3 March 2025 14 Tuesday 4 March 2025 15 Wednesday 5 March 2025 16 Thursday 6 March 2025 17 Friday 7 March 2025 18 Saturday 8 March 2025 19 Sunday 9 March 2025 20 Monday 10 March 2025 | décade 18 21 Tuesday 11 March 2025 22 Wednesday 12 March 2025 23 Thursday 13 March 2025 24 Friday 14 March 2025 25 Saturday 15 March 2025 26 Sunday 16 March 2025 27 Monday 17 March 2025 28 Tuesday 18 March 2025 29 Wednesday 19 March 2025 30 Thursday 20 March 2025 | Decimal time – 10 h/day Paris 5h57m82s Ventôse 13:13:55 Time of day - 24 h/day Greenwich |

## References to the calendar

The "Coup of 18 Brumaire" or "Brumaire" was the coup d'état of Napoleon Bonaparte on 18 Brumaire An VIII (9 November 1799), which many historians consider to be the end of the French Revolution. Karl Marx's 1852 essay The Eighteenth Brumaire of Louis Bonaparte compares the coup d'état of 1851 of Louis Napoléon unfavorably to his uncle's earlier coup, with the statement "History repeats ... first as tragedy, then as farce".
Another famous revolutionary date is 9 Thermidor An II (27 July 1794), the date the Convention turned against Maximilien Robespierre, who, along with others associated with the Mountain, was guillotined the following day. Based on this event, the term "Thermidorian" entered the Marxist vocabulary as referring to revolutionaries who destroy the revolution from the inside and turn against its true aims. For example, Leon Trotsky and his followers used this term about Joseph Stalin.
Émile Zola's novel Germinal takes its name from the calendar's month of Germinal.
The seafood dish Lobster Thermidor was named after the 1891 play Thermidor, set during the Revolution.
The French frigates of the Floréal class all bear names of Republican months.