The Revolutionary Months
1792 - 1806.
 
As a sign of the break with the old order the French Revolutionary Government adopted new names for the calendar months - words associated with the landscape and the actuality of the land.
 

Pluvoise
Ventose
Germinal
Floreal
Prairial
Messidor (June) see above
Thermidor
Fructidor
Vendemiarie
Brumaire
Frimaire
Nivose

The image, a print measuring 27 x 35 cms part of Les Mois Republicains and published in Paris.
 
A later published set faced the realties of events and the lettering was burnt out from the plate - and the names of the Gregorian calendar restored.