Soviet calendar for 1930 showing Gregorian months, coloured five-day work weeks, grouped into traditional seven-day weeks, with five national holidays.
From the autumn of 1929 until the summer of 1931, each Gregorian calendar year was usually divided into 72 five-day weeks (=360 days), three of which were split into two partial weeks by five national holidays. The two parts of each split week still totaled five days—the one or two national holidays that split it were not part of that week. Each day of the five-day week was labeled by either one of five colors or a Roman numeral from I to V. Each worker was assigned a color or number to identify his or her day of rest.
Eighty per cent of each factory’s workforce was at work every day (except holidays) in an attempt to increase production while 20% were resting. But if a husband and wife, and their relatives and friends were assigned different colors or numbers, they would not have a common rest day for their family and social life. Furthermore, machines broke down more frequently both because they were used by workers not familiar with them, and because no maintenance could be performed on machines that were never idle in factories with continuous schedules (24-hours/day every day).