As some other commenters pointed out, the comment (and the book) are not making claims about work hours. Seeing it from the perspective of "dawk to dusk" with o

As some other commenters pointed out, the comment (and the book) are not making claims about work hours. Seeing it from the perspective of "dawk to dusk" with our, now time-based perspective is the wrong interpretation of it because it imposes our view of work and time on a task-based life. You would work dawn til dusk, but you would: milk the cows at 06 AM, have a walk/chat/game with friends, bring the animals out, have breakfast, have a nap, refill water for animals, do some weeding, go have lunch with the other workers, etc. Then in the evening you bring the animals back in. So while you had a "15 hour workday" on the clock, your day is not consisting of actions and improvements without an end that can be done indefinitely, but by tasks that arise gradually at certain moments. All the time between the tasks is "time off" in the modern interpretation, and then you have a completely different view of work, because there is no pressure to produce at any point.