("Working 6 days a week in Canada in the 1960's.")

"By 1960, 37 to 40 hours during a five-day week had become the "standard." ......
"By the 1960s, almost 7 out of 10 full-time employees worked standard hours..... "...between 1964 and 1979, weekly manufacturing hours fell by less than an hour. Standard hours for all industries fell slightly more over this period from 40.1 to 38.3."

http://www.statcan.gc.ca/studies-etudes/75-001/archive/e-pdf/11-eng.pdf

As I remember the 1960s, with a major oil company in Canada; overtime was paid to union workers and hourly-pay employees with the company for any time worked over 40 hours. Moreover, hourly-pay employees on overtime were given meal allowances.