What was the name of the first month in the French Revolutionary Calendar?

The first month of the French Revolutionary Calendar was Vendémiaire. Its name came from vendange, referring to the grape harvest that takes place in France during early autumn.

The calendar was introduced during the French Revolution to replace the traditional Gregorian system and remove religious associations from public timekeeping. Its year began around the autumn equinox, and Vendémiaire generally ran from September 22 or 23 to October 21 or 22, depending on the year.

Each month contained 30 days, divided into three ten-day weeks called décades. The calendar had twelve regular months, followed by five or six additional complementary days at the end of the year. Other autumn months included Brumaire, named for mist, and Frimaire, associated with frost.

Vendémiaire also appears in famous revolutionary dates. The royalist uprising of 13 Vendémiaire Year IV, corresponding to October 5, 1795, was suppressed by troops commanded by the young Napoleon Bonaparte. The calendar was eventually abandoned under Napoleon in 1806, although it remained an important symbol of revolutionary attempts to remake everyday life.