Doctors, executives and human resource experts say a four-day workweek would be great for the American workforce. We would have more time to see the dentist, hang out with our children and get errands done. We would be happier, and our morale would improve.

It’s believed that when there's less time to work, you waste less time. When you have a compressed workweek, you tend to focus on what's important.

Of the different was they are described at Forbes I liked this one the best. They said:

"Four-day workweeks can be done in many ways, with varying hours. For example, the 5-4/9 arrangement lets staffers alternate between weeks of five nine-hour days and ones with four nine-hour days, so you get a day off every other week."