Messidor was the French Republican calendar month that began around the summer solstice. It was the tenth month of the revolutionary calendar and generally started on 19 or 20 June in the Gregorian calendar.
The name Messidor comes from the Latin messis, meaning “harvest.” Its agricultural name matched the calendar’s broader aim of replacing traditional religious and royal references with terms drawn from nature, farming and seasonal life. Messidor was the first month of the calendar’s summer quarter.
Each Republican month lasted 30 days and was divided into three décades, or groups of ten days. Messidor therefore ran for 30 days, usually ending on 18 or 19 July, before Thermidor began. Its days were also given nature-themed names, including crops, plants, animals and agricultural tools.
The French Republican calendar was introduced during the French Revolution and used by the government from 1793 until 1805. It began each year at the autumnal equinox, rather than on 1 January. Prairial preceded Messidor, while Thermidor followed it; Fructidor came later in the summer. The month should not be confused with Thermidor, whose name is associated with heat and the revolutionary month that gave its name to the Thermidorian Reaction.