It so happened that at the beginning of the 20th century, the Russian Orthodox Church did not switch from the Julian calendar to the new Gregorian one, as a result of which the calendar differs by 13 days from the calendar used by other Christians.

So, Christmas Day as a holiday in Russia differs significantly from its counterpart in the rest of the Christian world.

Initially, the Christmas holidays were associated with many folk customs, but they were forgotten after the celebration of Christmas in Russia was banned in 1918.

Only in 1935 did the Soviet government again allow the installation and decoration of Christmas trees with one difference, it is generally not referred to as Christmas trees but New Year's trees.

And the stars on the top of the spruce became five-pointed in the Soviet style.

Source:https://www.nst.com.my/opinion/columnists/2024/01/1001107/unique-new-year-and-christmas-celebration-russia