В 1918 г. подписан Декрет СНК РСФСР «О введении в Российской республике западноевропейского календаря»

There are practically no sources where the old and the new styles are not mixed, the dates are not shifted and duplicated on different days of a specific event. The reason for this is buried in centuries: in 1582, at the initiative of Pope Gregory XIII, the countries of the Catholic world, i.e., civilized countries according to the old and modern standards, introduced a new calendar called the Gregorian calendar. Due to theological differences, the Russian Orthodox Church did not switch to the new style. Therefore, dedicated and militant atheists had to save the situation. On January 26, 1918, authorities signed the Decree of the Council of People’s Commissars of the Russian Soviet Federative Socialist Republic to introduce “the same reckoning of time with almost all cultural peoples” and established: “The first day after January 31 of a given year shall be considered February 14th and not February 1st.” Thus, if you see the date of February 5, 1918, do not believe it – it did not exist.