May 1, 1926
Ford Motor Company's factory workers go to 5-day, 40-hour week
In March 1926, Edsel Ford, President of Ford Motor Company, announced Ford's factory workers would go to a 5-day, 40-hour work week effective May 1. His father, and founder of the company, agreed saying, "It is high time to rid ourselves of the notion that leisure for workmen is either 'lost time' or a class privilege."
Office staff went to a 40-hour week in August that same year.