> Using a Gregorian Date before the calendar was introduced is almost certainly an error. It's just an extrapolation; using the calendar being used at the cons

> Using a Gregorian Date before the calendar was introduced is almost certainly an error. It's just an extrapolation; using the calendar being used at the considered time would be meaningless for us, e.g. the short-lived french republican calendar [1]. [1] https://en.wikipedia.org/wiki/French_Republican_calendar https://en.wikipedia.org/wiki/French_Republican_calendar