In 72-73 worked at a paper mill on rotating shifts. Best I remember started Monday at midnight. Worked 5, then off 2, came back on second shift, 5 on and one off, then 5 days on, one off, 5 more days, then a 5 day weekend. Sundays were double pay, any week over 40 got time and a half. Averaged 42 hours a week.