There is probably a unique holiday in Russia. It is called Old New Year. How can such an oxymoron exist?
At the beginning of the 20th century here the old Julian calendar was used. But already in 1918, the Bolshevik authorities decided to change the Russian chronology to the Gregorian calendar adopted in most European countries. By that time, the difference between the Julian and Gregorian calendars was 13 days, that was greatly complicates. And in February a decree on the introduction of a Western European calendar was adopted in the Russian Republic. In this year after January 31 immediately was February 14.
In the public mind, two versions of the calendar “old style” and “new style” somehow got along.
In the new style, the new year has already arrived, but in the old style the country has not yet celebrated Christmas, which always preceded it. By the way, the Russian Orthodox Church did not agree with the change of the calendar, and continued to conduct its annual circle of services in the Julian style. Therefore, in Russia we celebrate Christmas not on December 25, but on January 7.