[robin_reala]

France might first have switched in 1582, but that ignores the bit in the middle where they decimalised time and reset the year counter: https://en.wikipedia.org/wiki/French_Republican_Calendar

[B1FF_PSUVM]

We don't talk about that.

(Unless you read stuff such as Karl M.'s 18th Brummaire of Louis Bonaparte, but then you're beyond help.)