Until the early 1930s, the only day of rest in America was typically the Sabbath (for Christians Sunday, for Jews Saturday). During the Depression there was a demand for “sharing the work,” which resulted in codes of fair competition, which created the 40-hour, 5-day work week. These codes were adopted in the National Industrial Recovery Act of 1933. This act was later deemed unconstitutional, but the practice remained. In 1938 the Fair Labor Standards Act renewed the 40-hour week’s basis in law by stipulating that hours worked in excess of 40 were to be compensated at one and one-half times the normal rate.
Now I finally understand the lyrics of that one song… “Everybody’s working for the weekend (thanks to the National Industrial Recovery Act of 1933, which, although unconstitutional, created the weekend that we are working for)!”
It’s in parentheses because only the background singers sing it.