Christmas was celebrated December 25th before the Gregorian calendar switch.

[LiberalFighter]

Sometime around 800 AD during the Charlemagne Christmas became a major celebration. What would be the equivalent date in 2023?

[IbogaProject]

1. our calendar is the Julian, so I looked up a conversion

Gregorian date to Julian date
Date
Mon 25 December 2023
Century 21st
Year 2023
Month
12
Day
12

[muriel_volestrangler]

2. 10 days were skipped in 1582 in the Catholic country conversion

Friday 15th October followed Thursday 4th October: https://en.wikipedia.org/wiki/Gregorian_calendar
So Dec 25th 1581 in the Julian calendar was January 5th 1582 Gregorian (if someone had been using it then).
But the Julian calendar used leap days in 1500, 1400, 1300, 1100, 1000 and 900 when the Gregorian calendar would not have.
So the 10 day difference is decreased to just 4 days in 800.
So Dec 25th 800 (Julian) was Dec 29th 800 (Gregorian).

When you ask "the equivalent date in 2023", are you asking "how many days after the winter solstice was Christmas (Julian) in 800, so how many days after the winter solstice should we put Christmas now?" (the point of the conversion was to keep the dates of the solstices and equinoxes as stable as possible). I think the answer to that should be "Dec 29th", but someone should check my logic.