Four days on and three off is nice. I've done that. Best work on/off experience I've had was job-shares. You have one job, two workers. Worker One starts at noon Wednesday, works Thursday and Friday, has the weekend off, works Monday, Tuesday and Wednesday until one. Then takes a week off. There's the one hour overlap to inform Worker Two of important job stuff. This doesn't work with all jobs, but it does for lots of them.

It works especially well for people who have a second calling which brings in some income, but is not entirely reliable, such as a craft, art, or profession. In times of high unemployment, it means one job serves two people, which is how I first encountered the concept, after which I sought it out. Some employers like it because they get two workers knowing the same job, neither is exhausted from overwork, if one is ill, the other is normally willing to fill in for the extra cash, and any sudden overload of work can be handled by having both on the job for as long as needed.