There is a recent article in The Atlantic magazine titled "Where the Five-Day Workweek Came From", which delves into the history of the now-common seven-day period of five days at work, two days off. It also champions the prospect of a four-day workweek, which, according to the article, "would lead to increased productivity, improved health, and higher employee-retention rates."
I think there are other benefits to consider. In a scenario involving 10-hour days, four days per week, a mother or father would work two extra hours per day but have three whole days with their family. They would then have not just more time to spend together, but money as well, thereby boosting national consumer spending.
This is a great country - our citizens deserve a better balance of work and play.