fun fact: Thermidor - after which Sauce Thermidor and derived dishes like Lobster Themidor are named, is a month in the French Republican Calendar, specifically: the second month of summer, going approx. from mid-July to mid-August.
Autumn:
Vendémiaire (from French vendange, derived from Latin vindemia, "vintage"), starting 22, 23, or 24 September
Brumaire (from French brume, "mist", from Latin brūma, "winter solstice; winter; winter cold"), starting 22, 23, or 24 October
Frimaire (from French frimas, "frost"), starting 21, 22, or 23 November
Winter:
Nivôse (from Latin nivosus, "snowy"), starting 21, 22, or 23 December
Pluviôse (from French pluvieux, derived from Latin pluvius, "rainy"), starting 20, 21, or 22 January
Ventôse (from French venteux, derived from Latin ventosus, "windy"), starting 19, 20, or 21 February
Spring:
Germinal (from French germination), starting 20 or 21 March
Floréal (from French fleur, derived from Latin flos, "flower"), starting 20 or 21 April
Prairial (from French prairie, "meadow"), starting 20 or 21 May
Summer:
Messidor (from Latin messis, "harvest"), starting 19 or 20 June
Thermidor (or Fervidor*) (from Greek thermon, "summer heat"), starting 19 or 20 July
Fructidor (from Latin fructus, "fruit"), starting 18 or 19 August
This Republican calendar is also a source of headaches for students studying the French Revolution because while it didn’t stick, it stuck around long enough to matter and for historians to need to deal with it in primary sources.