Your challenge, should you choose to accept it, is to either...
a. Prevent the French Republican Calendar from being abolished in 1805.
or...
b. Have the calendar be adopted at a later time (like how it was re-adopted by the Paris Commune), for a period of at least fifteen years, by an established country. Calendars based on the FRC are acceptable.
The parameters:
---The ten hour day must be adopted as well.
---You cannot change the original FRC in any way, though you can have limited reforms later on, or calendars based heavily on the FRC.
---The calendar must reach wide usage in the country where it's being adopted.
a. Prevent the French Republican Calendar from being abolished in 1805.
or...
b. Have the calendar be adopted at a later time (like how it was re-adopted by the Paris Commune), for a period of at least fifteen years, by an established country. Calendars based on the FRC are acceptable.
The parameters:
---The ten hour day must be adopted as well.
---You cannot change the original FRC in any way, though you can have limited reforms later on, or calendars based heavily on the FRC.
---The calendar must reach wide usage in the country where it's being adopted.