The month and day names were created by poet Fabre D' Eglantine. Each season had the same suffix : -aire for fall, -ose for the winter, -al for spring and -or for summer (because of the gold color of the sun ?). Month prefix reflected the climatic / agricultural spirit of the month, probably to exhalt the agricultural identity of France.

Vendémiaire (from vendanges - vintage)
Brumaire (from Brume - fog)

Nivôse (from the latin for snow)
Pluviôse (from pluvieux - rainy)
Ventôse (from venteux - windy)

Germinal (from germination)
Floréal (from flowers)
Prairial (from prairie)

Messidor (from moisson - harvest)
Thermidor (for thermos -heat)
Fructidor (from fruits)

The saints of every day (like St-Glinglin, St-Jean etc) were also replaced by farm things, like carrot, straw etc.
The officials shot in their own feet from the beginning, allowing their administration employees to take off every sunday, only a few years after introduction.