Conceived by Fabre d’Eglantine and decreed by the National Convention in 1793, the Revolutionary Calendar took advantage of the Republic’s creation on the autumnal equinox, and revealed something of the republican fixation with Nature and the “natural” order. Thus the names of the months were based on seasonal realities as reflected in the climate of Paris. With the advent of the Empire, however, the new system became increasingly suggestive of the excesses of the Revolution, and on January 1, 1806, in a gesture of conciliation toward the Church, Napoleon officially restored the Gregorian calendar.
AUTUMN
VENDEMIAIRE (month of vintage) 22 September–21 October
BRUMAIRE (month of fog) 22 October–20 November
FRIMAIRE (month of frost) 21 November–20 December
WINTER
NIVOSE (month of snow) 21 December–19 January
PLUVIOSE (month of rain) 20 January–18 February
VENTOSE (month of wind) 19 February–20 March
SPRING
GERMINAL (month of budding) 21 March–19 April
FLOREAL (month of flowers) 20 April–19 May
PRAIRIAL (month of meadows) 20 May–18 June
SUMMER
MESSIDOR (month of harvest) 19 June–18 July
THERMIDOR (month of heat) 19 July–17 August
FRUCTIDOR (month of fruit) 18 August–16 September
Sans-culottides: 17-21 September