For a few years I lived my life rigorously to the beat of the french revolutionary calendar - i was very enamoured by its consistent month partitioning, and dumping the leap day at the end of the year's festival days. The major downside is that the months were named after French seasonal characteristics, which... doesn't really work.
I gave it an honest try, but I found it much harder to adapt to than the calendar. I could just about do head-conversion for dates between Gregorian and Revolutionary calendars for things like appointments, but found it much harder to do it for both dates and time. I still have a love for the system, though.
