French Republican calendar

The  (French: 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  in 1871, and 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 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.

Quotes

 * The Jacobin push to restart the French calendar with Year Zero was intended to create a new France, free of the vestiges of the past and able to be warped to fit the whims of the new ruling class. If you can control how we perceive time itself, you can manipulate society and culture in any way you see fit — which is exactly why the left seeks to gain this control for itself.
 * Mike Coté, "It’s Time To Ditch LGBT Month For A Holiday We Can All Take Pride In", The Federalist (May 29, 2024)