{"id":3508,"date":"2026-03-08T18:23:02","date_gmt":"2026-03-08T17:23:02","guid":{"rendered":"https:\/\/www.gironi.it\/blog\/the-french-revolutionary-calendar\/"},"modified":"2026-03-08T18:29:13","modified_gmt":"2026-03-08T17:29:13","slug":"the-french-revolutionary-calendar","status":"publish","type":"post","link":"https:\/\/www.gironi.it\/blog\/en\/the-french-revolutionary-calendar\/","title":{"rendered":"The French Revolutionary Calendar"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Date Converter<\/h2>\n\n\n\n<p>Use the converter to transform any Gregorian date into the corresponding French Revolutionary calendar date, and vice versa. The algorithm uses historically verified equinox dates for years I-XIV (1792-1805) and the Romme method for later dates.<\/p>\n\n\n\n<!--more-->\n\n\n\n<iframe loading=\"lazy\" src=\"https:\/\/www.gironi.it\/utility\/calendario-rivoluzionario-en\/\" width=\"100%\" height=\"500\" frameborder=\"0\" style=\"border:none; border-radius:8px;\"><\/iframe>\n\n\n\n<h2 class=\"wp-block-heading\">History of the Revolutionary Calendar<\/h2>\n\n\n\n<p>The French Revolutionary calendar, also known as the <strong>Republican calendar<\/strong>, was one of the most ambitious projects of the French Revolution: redesigning time itself. It was not a simple renaming exercise, but a radical restructuring of how the French measured days, weeks, and years.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"260\" height=\"191\" src=\"https:\/\/www.gironi.it\/blog\/wp-content\/uploads\/2017\/09\/calendario-rivoluzione.jpg\" alt=\"French Revolutionary Calendar\" class=\"wp-image-518\"\/><\/figure>\n<\/div>\n\n\n<p><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Why a New Calendar?<\/h3>\n\n\n\n<p>The revolutionaries saw the Gregorian calendar as a symbol of the Ancien Regime and the power of the Catholic Church. Every day was dedicated to a saint, holidays marked the liturgical year, and the seven-day week had biblical origins. To build a society based on reason and nature, a new calendar was needed.<\/p>\n\n\n\n<p>The idea was part of a broader <strong>decimalization<\/strong> project that included the metric system (still in use) and decimal time (abandoned). The calendar was meant to reflect nature, seasons, and agricultural work instead of saints and religious holidays.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Who Created It<\/h3>\n\n\n\n<p>The calendar was the result of the work of two key figures:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Gilbert Romme<\/strong> (1750-1795), mathematician and deputy, designed the mathematical structure: 12 months of 30 days, decades of 10 days, complementary days.<\/li>\n\n\n\n<li><strong>Fabre d&#8217;Eglantine<\/strong> (1750-1794), poet and playwright, devised the evocative month names and created the rural calendar, assigning each day a name connected to nature.<\/li>\n<\/ul>\n\n\n\n<p>The decree was approved on 24 October 1793 (3 Brumaire An II) by the National Convention.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Period of Use<\/h3>\n\n\n\n<p>The calendar was in effect from <strong>22 September 1792<\/strong> to <strong>1 January 1806<\/strong>, when Napoleon abolished it. It was briefly revived during the <strong>Paris Commune<\/strong> in 1871, for just 18 days.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">How the Revolutionary Calendar Works<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">The 12 Months and Their Meaning<\/h3>\n\n\n\n<p>Fabre d&#8217;Eglantine chose names that evoked the weather and agricultural conditions of each period. The months are grouped into four seasons, recognizable by their suffix:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Season<\/th><th>Month<\/th><th>Meaning<\/th><th>Approx. Gregorian Period<\/th><\/tr><\/thead><tbody><tr><td rowspan=\"3\"><strong>Autumn<\/strong> (-aire)<\/td><td>Vendemiaire<\/td><td>Grape harvest<\/td><td>22 Sep &#8211; 21 Oct<\/td><\/tr><tr><td>Brumaire<\/td><td>Fog, mist<\/td><td>22 Oct &#8211; 20 Nov<\/td><\/tr><tr><td>Frimaire<\/td><td>Frost<\/td><td>21 Nov &#8211; 20 Dec<\/td><\/tr><tr><td rowspan=\"3\"><strong>Winter<\/strong> (-ose)<\/td><td>Nivose<\/td><td>Snow<\/td><td>21 Dec &#8211; 19 Jan<\/td><\/tr><tr><td>Pluviose<\/td><td>Rain<\/td><td>20 Jan &#8211; 18 Feb<\/td><\/tr><tr><td>Ventose<\/td><td>Wind<\/td><td>19 Feb &#8211; 20 Mar<\/td><\/tr><tr><td rowspan=\"3\"><strong>Spring<\/strong> (-al)<\/td><td>Germinal<\/td><td>Germination<\/td><td>21 Mar &#8211; 19 Apr<\/td><\/tr><tr><td>Floreal<\/td><td>Flower<\/td><td>20 Apr &#8211; 19 May<\/td><\/tr><tr><td>Prairial<\/td><td>Meadow<\/td><td>20 May &#8211; 18 Jun<\/td><\/tr><tr><td rowspan=\"3\"><strong>Summer<\/strong> (-idor)<\/td><td>Messidor<\/td><td>Harvest<\/td><td>19 Jun &#8211; 18 Jul<\/td><\/tr><tr><td>Thermidor<\/td><td>Heat<\/td><td>19 Jul &#8211; 17 Aug<\/td><\/tr><tr><td>Fructidor<\/td><td>Fruit<\/td><td>18 Aug &#8211; 16 Sep<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>The suffixes make it easy to identify the season: <strong>-aire<\/strong> for autumn, <strong>-ose<\/strong> for winter, <strong>-al<\/strong> for spring, <strong>-idor<\/strong> for summer.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">The Decade: 10-Day Weeks<\/h3>\n\n\n\n<p>The week was replaced by the <strong>decade<\/strong>, a 10-day period. The days were called: Primidi, Duodi, Tridi, Quartidi, Quintidi, Sextidi, Septidi, Octidi, Nonidi, Decadi (rest day).<\/p>\n\n\n\n<p>The decade was one of the most unpopular aspects of the calendar: workers went from one rest day every 7 to one every 10.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">The Sansculottides: Complementary Days<\/h3>\n\n\n\n<p>With 12 months of 30 days we reach 360, leaving 5 days short (6 in leap years). These days, called <strong>Sansculottides<\/strong>, fell at the end of the year and were dedicated to republican values: Virtue, Genius, Labour, Opinion, Rewards, and Revolution (leap years only).<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Leap Years and the Autumnal Equinox<\/h3>\n\n\n\n<p>The republican year began on the day of the <strong>autumnal equinox<\/strong>. During the historical period (years I-XIV), leap years were <strong>III, VII, and XI<\/strong>. For later dates, the <strong>Romme method<\/strong> is used: divisible by 4, not by 100, unless by 400.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Famous Dates in the Revolutionary Calendar<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Republican Date<\/th><th>Gregorian Date<\/th><th>Event<\/th><\/tr><\/thead><tbody><tr><td>1 Vendemiaire An I<\/td><td>22 September 1792<\/td><td>Proclamation of the Republic<\/td><\/tr><tr><td>2 Pluviose An I<\/td><td>21 January 1793<\/td><td>Execution of Louis XVI<\/td><\/tr><tr><td>12 Germinal An II<\/td><td>1 April 1794<\/td><td>Abolition of slavery in French colonies<\/td><\/tr><tr><td><strong>9 Thermidor An II<\/strong><\/td><td>27 July 1794<\/td><td>Fall of Robespierre, end of the Terror<\/td><\/tr><tr><td>13 Vendemiaire An IV<\/td><td>5 October 1795<\/td><td>Napoleon suppresses the royalist uprising<\/td><\/tr><tr><td>18 Fructidor An V<\/td><td>4 September 1797<\/td><td>Directory coup against monarchists<\/td><\/tr><tr><td><strong>18 Brumaire An VIII<\/strong><\/td><td>9 November 1799<\/td><td>Napoleon&#8217;s coup d&#8217;etat<\/td><\/tr><tr><td>11 Frimaire An XIII<\/td><td>2 December 1804<\/td><td>Napoleon&#8217;s coronation as Emperor<\/td><\/tr><tr><td>10 Nivose An XIV<\/td><td>31 December 1805<\/td><td>Last day of the calendar<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>The expressions <strong>&#8220;9 Thermidor&#8221;<\/strong> and <strong>&#8220;18 Brumaire&#8221;<\/strong> have become universal synonyms for &#8220;counter-revolutionary reaction&#8221; and &#8220;military coup d&#8217;etat&#8221; respectively. Karl Marx wrote in <em>The Eighteenth Brumaire of Louis Bonaparte<\/em> (1852) the famous phrase: &#8220;history repeats itself, first as tragedy, then as farce.&#8221;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">The Rural Calendar: A Name for Every Day<\/h2>\n\n\n\n<p>Every day of the year bore the name of a natural element: Quintidi days were named after an animal, Decadi days after an agricultural tool, and all other days after plants, flowers, or minerals. Examples: 1 Vendemiaire = Grape, 5 Floreal = Nightingale, 27 Messidor = Strawberry.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Trivia and Pop Culture<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Lobster Thermidor<\/strong>: the famous dish is named after the summer month<\/li>\n\n\n\n<li><strong>Germinal by Zola<\/strong>: the 1885 novel takes its title from the spring month<\/li>\n\n\n\n<li><strong>The Paris Commune<\/strong> (1871) briefly restored the calendar<\/li>\n\n\n\n<li>The <strong>metric system<\/strong> is the only decimal reform of the Revolution that survived<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Frequently Asked Questions<\/h2>\n\n\n\n<div>\n<div>\n<h3>When does the year begin in the Revolutionary calendar?<\/h3>\n<div>\n<p>The republican year begins on the day of the autumnal equinox, usually 22 or 23 September. Year I began on 22 September 1792.<\/p>\n<\/div>\n<\/div>\n<div>\n<h3>What is 18 Brumaire?<\/h3>\n<div>\n<p>18 Brumaire An VIII (9 November 1799) is the date of Napoleon&#8217;s coup d&#8217;etat. The expression has become synonymous with military coup.<\/p>\n<\/div>\n<\/div>\n<div>\n<h3>How long was the Revolutionary calendar in use?<\/h3>\n<div>\n<p>It was in effect for about 13 years, from 22 September 1792 to 1 January 1806. It was briefly revived during the Paris Commune in 1871.<\/p>\n<\/div>\n<\/div>\n<div>\n<h3>What are the Sansculottides?<\/h3>\n<div>\n<p>They are the 5 or 6 complementary days at the end of the year, dedicated to republican values: Virtue, Genius, Labour, Opinion, Rewards, and Revolution (leap years only).<\/p>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<script type=\"application\/ld+json\">\n  {\n    \"@context\": \"https:\/\/schema.org\",\n    \"@type\": \"FAQPage\",\n    \"mainEntity\": [\n      {\n        \"@type\": \"Question\",\n        \"name\": \"When does the year begin in the Revolutionary calendar?\",\n        \"acceptedAnswer\": {\n          \"@type\": \"Answer\",\n          \"text\": \"The republican year begins on the day of the autumnal equinox, usually 22 or 23 September. 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The algorithm uses historically verified equinox dates for years I-XIV (1792-1805) and the Romme method for later dates.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_uag_custom_page_level_css":"","footnotes":""},"categories":[1274],"tags":[],"class_list":["post-3508","post","type-post","status-publish","format-standard","hentry","category-history"],"lang":"en","translations":{"en":3508},"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"post-thumbnail":false},"uagb_author_info":{"display_name":"autore-articoli","author_link":"https:\/\/www.gironi.it\/blog\/author\/autore-articoli\/"},"uagb_comment_info":1,"uagb_excerpt":"Date Converter Use the converter to transform any Gregorian date into the corresponding French Revolutionary calendar date, and vice versa. The algorithm uses historically verified equinox dates for years I-XIV (1792-1805) and the Romme method for later dates.","_links":{"self":[{"href":"https:\/\/www.gironi.it\/blog\/wp-json\/wp\/v2\/posts\/3508","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gironi.it\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gironi.it\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gironi.it\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gironi.it\/blog\/wp-json\/wp\/v2\/comments?post=3508"}],"version-history":[{"count":2,"href":"https:\/\/www.gironi.it\/blog\/wp-json\/wp\/v2\/posts\/3508\/revisions"}],"predecessor-version":[{"id":3511,"href":"https:\/\/www.gironi.it\/blog\/wp-json\/wp\/v2\/posts\/3508\/revisions\/3511"}],"wp:attachment":[{"href":"https:\/\/www.gironi.it\/blog\/wp-json\/wp\/v2\/media?parent=3508"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gironi.it\/blog\/wp-json\/wp\/v2\/categories?post=3508"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gironi.it\/blog\/wp-json\/wp\/v2\/tags?post=3508"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}