That's true, but in terms of 'fully free' days it does apply. For example, I'd bet most people would be unwilling to smooth over their 40 hour workweek over th

That's true, but in terms of 'fully free' days it does apply. For example, I'd bet most people would be unwilling to smooth over their 40 hour workweek over the course of the full week of 7 days, working 5.7 hours a day. Of course that's nice in a way, but having no fully free days and perpetually working forever, is agonising. In that sense you can't just compare cutting a working day to simply having more discretionary time (which you have after workdays, too). Fully free days count a bit differently.