French Republican Calendar
The French Republican calendar, also known as the French Revolutionary calendar, was created during the French Revolution (1789-1799) in an attempt to build a new society separate from the vestiges of the Ancien Régime. First implemented in 1793, the calendar remained in use for twelve years until 1806 and was revived for 18 days during the Paris Commune of 1871.
The Republican calendar was designed to remove all royalist and Christian elements from the French calendar, which were replaced by natural and agricultural motifs. This is apparent in the poetic names of the months, derived from the most prominent characteristic of each month. For example, the month of Thermidor, which lasted from mid-July to mid-August in the Gregorian calendar, was derived from the Greek word thermon or “summer heat.” The calendar is also notable for its use of decimal time. Each week consisted of ten days, and each day consisted of ten hours. An hour was made up of 100 decimal minutes, which were in turn divided into 100 decimal seconds.