Well... if you make both quintidi and decadi free days for workers, and if you prevent/solve infighting within the government à la USSR, the calendar alone should not be a reason for the gov't to fall too soon...
You are a French Revolutionary Calendar geek! I was not aware that so much information about its history had survived to the present day! Hats off to your research skills!
I intended for the United French Revolutionary Communes to have a sort of semi-anarchist, semi-Left SR (I apologize for the fact that all my comparisons are Russian), but it's not like its historical predecessors didn't lean on the whole "send the counterrevolutionaries to the gulags/guillotines!" sort of mentality. After the RSFSR was smashed by the Germans, the UFRC probably learned to keep its mouth shut, especially towards German allies, so at least that shouldn't (emphasis on
shouldn't) be a problem.
As to the days off, hopefully a state run by
polius and workers will at least have a workable industrial economy, but it shouldn't be much of a problem, what with most of France's goods being imported from Turkey (currently undergoing an enourmous development program under the oversight of Kemal and the funding of the country's absurdly plentiful oil reserves) and the US due to almost all of its factories having been destroyed by German occupiers and revolutionary saboteurs.
