But that calendar was used only for a few years.

"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 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 briefly used again for a few weeks of the Paris Commune, in May 1871."