I am curious which leap day system you use for the French Republican calendar. Most popular versions of the calendar I see floating around just use the Gregorian leap year system, which I don't like because it yields the wrong results in the year the calendar was in use. Yet, I don't see mental math as a viable option when using the original date-of-equinox method used during the revolution.
It's not an easy thing; frankly, if I have to back convert to prior times when the Calendar was still in use, you have to just swallow the pill
However, if using the calendar in day to day life, the Revised System is much easier.
To quote Wikipedia:
leap years being every year divisible by 4, except years divisible by 100 and not by 400. Years divisible by 4000 would also be ordinary years. This calendar also has the benefit that every year in the third century of the Republican Era (1992–2091) begins on 22 September.
