The 5-day week is archaic today's society.
Our understanding of the intricacies of business includes a need for productivity and worker satisfaction. Very few workers would not be satisfied with an extra day on the weekend.
The 4-day week would remove 52 days per year of rush hour traffic congestion, thus increasing air quality.The energy benefits gained from office buildings being closed 52 extra days per year would be astronomical from a conservation standpoint.
On the plus side for employers, happier employees are more productive. Overtime pay would not be as necessary, health benefits become less costly and overhead costs drop dramatically.
This is a win-win for business and labor.
Life was meant for living; Lets make some time for it.