Soviet calendar

The Soviet calendar was a modified Gregorian calendar that was used in Soviet Russia between 1918 and 1940. Several variations were used during that time.

The Gregorian calendar, under the name "Western European calendar", was implemented in Soviet Russia in February 1918 by dropping the Julian dates of 1–13 February 1918. As many as nine national holidays (paid days of rest) were implemented in the following decade, but four were eliminated or merged on 24 September 1929, leaving only five national holidays: 22 January, 1–2 May, and 7–8 November until 1951, when 22 January reverted to a normal day.

During the summer of 1929, five-day continuous work weeks were implemented in factories, government offices, and commercial enterprises, but not collective farms. One of the five days was randomly assigned to each worker as their day of rest; the purpose of this system was to allow factories to operate every day, always having most of its workers present to maintain production. These five-day work weeks continued throughout the Gregorian year, interrupted only by the five national holidays. While the five-day week was used for scheduling work, the Gregorian calendar and its seven-day week were used for all other purposes.

During the summer of 1931, six-day interrupted work weeks were implemented for most workers, with a common day of rest for all workers interrupting their work weeks. Five six-day work weeks were assigned to each Gregorian month, more or less, with the five national holidays converting normal work days into days of rest.