Following some discussion about whether 24 Dec 1811 fell on Shabbas, Michael
This was about the time that most European nations adjusted theMichael is correct to raise the consideration of the shift >from Julian to
Gregorian calendar, which occurred at different times in different
countries. Catholic nations generally changed in 1582, while many Protestant
nations did not change until as late as 1752 (eg British Empire), and
eastern Orthodox nations mostly changed in the early 20th century. This is
important when trying to figure out "what day of the week was Jan 1, 1700"
(answer is, it depends which country).
However, France changed their calendar in 1582, so by the date in question
in 1811, France had been on the Gregorian calendar for over a couple
centuries, and 24 Dec 1811 was indeed a Tuesday as has been pointed out.
Michael is also correct in noting that France had an entirely unique
calendar system for a brief period, a by-product of Revolutionary
exuberance. However, the Republican calendar was only in effect >from 1793 to
1806. Also, it was a complete overhaul of the traditional calendar, with the
new year starting on the fall equinox, 12 months of exactly 30 days each
(with completely new month names), and the traditional 7-day week abolished
in favor of a 10-day week called a "decade". (Since 12 30-day months only
makes 360 days, they had a handful of festival days at the end of each year
that didn't belong to any month.)
Had France still been on the Republican calendar on the date in question (24
Dec 1811), I estimate that it would have fallen on the second day ("Duodi")
of the first 10-day "decade" in the fourth month ("Nivo^se") of the year 18.
In other words, there would be no confusion should you come across a
Republican date in France, because it would look completely unlike a Julian
or Gregorian date.
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