The Soviet revolutionary calendar was in use in the Soviet Union from 1929 to 1940. Shortly after the October Revolution of 1917, Vladimir Lenin had decreed to change the calendar in the Soviet Union from the Julian Calendar to the Gregorian calendar. This change involved bypassing the days from February 1 until February 13 1918. * Lenin day after January 30 * Labour Days, two days after April 30 * Industry Days, two days after November 7 * in leap years, a leap day after February 30