In Ada Palmer's Terra Ignota series, set in the 2400's, most people work 20 hour weeks with the rest of their time spent on hobbies. A minority of people, whose jobs are their passions, work significantly more than 20 hours, this is termed Voking (as in, to be a vocateur) and is considered kinda unusual.

Reading between the lines, I think full automation is entirely possible in the setting but the world naturally settled on a 20 hour week to give everyone the benefits of purpose etc.