4-day weeks always seem compelling to me because each day you work of a 5-day week gives you 0.4 weekend days, but each day you work out of a 4-day week gives you 0.75 weekend days.

you work 20% less, but you get almost twice as many rest days per non-rest day

A very liberal piece, but it's nice to see this finally entering the mainstream discussion. Of course, we could go so much further than just a 4-day work week of 8 hour days:

by working 4 or 5 hours a day till the age of forty-five or fifty, man could easily produce all that is necessary to guarantee comfort to society.
— Kropotkin, The Conquest of Bread

Just imagine how much we could do with the remaining time. We could dedicate ourselves to higher learning, to the creation of art and literature, to the building of community and betterment of all.