Winter events
The winter of 2023/2024 was quite effectively prepared for this time by the prematurely wintry weather, especially in the last month of the still formally prevailing astronomical autumn.
Regardless of the weather, however, the official start of astronomical winter falls this time as predicted on December 22 at. 4:27 a.m. Central European Winter Time (CET). It is perhaps worth recalling that in our time the moment of the winter solstice, identified with the beginning of astronomical winter, usually falls on December 21, less often on December 22. The reason lies in the difference in the length of the calendar year (365 or 366 days, 365.2425 on average) and the stellar year, equal to the period of the Earth’s rotation around the Sun (365.256363 days). To keep the calendar in line with the seasons, the difference is corrected through a system of leap years, in which February is 1 day longer. Recall that in the 1582 in force. Gregorian calendar, by 1 day longer leap years are those whose number is divisible by 4, but only every fourth divisible by 100, except divisible by 400. For example: the leap years 1600 and 2000 were leap years, while the years 1700, 1800 and 1900 were ordinary; so the year 2100 will also be unleap years.
Jan Desselberger
Read more: https://www.sigma-not.pl/publikacja-146586-zimowe-wydarzenia-przeglad-techniczny-2023-12.html
