The Julian calendar, the predecessor to the modern Gregorian calendar, didn’t quite fully account for leap year shenanigans, and so drifted be about 1 day every century. The Gregorian calendar changed the way leap year works, but didn’t reset the beginning of the year. It just froze the drift where it was at the time.
I mean, winter solstice is a little more than a week away, I’d say that was probably a significant influence on the designation of end of the year.
The Julian calendar, the predecessor to the modern Gregorian calendar, didn’t quite fully account for leap year shenanigans, and so drifted be about 1 day every century. The Gregorian calendar changed the way leap year works, but didn’t reset the beginning of the year. It just froze the drift where it was at the time.
https://en.m.wikipedia.org/wiki/Gregorian_calendar