Longer than that. In WW2, factories increased hours to 60 to increase production. The workers were all on board with this. Production increased for a while, and then dipped below the 40 hour results.
Some experimentation showed that to get a sustained increase in production, the working hours would be increased for a time, and then brought back to 40, back and forth.
Personally, I'm well aware that when my tiredness exceeds a certain level, any programming work I do has to be undone (thank you, git!) and redone after I'm rested. What I do when I want to work, but am tired, is work on things that don't require much attention, like organizing my office, making backups, etc.
Its very interesting--the research they present suggests that people worked much less before industrialization. It jumped massively as lots of low-skill people took factory jobs for the first time and worked 12+16 hour days, but since then has steadily declined again.
This was the big takeaway for me:
"...some of the leading economic thinkers of the last century expected the gradual shortening of the work week would just keep going. None other than John Maynard Keynes, one of the most important figures in economics - and imaginary friend to the show - famously predicted that we would all be working a 15-hour work week by 2030."
The Hawthorne experiment found something similar. If I remember it correctly. Both increasing/reducing the illumination in a factory resulted in increased productivity. Unfortunately I think managerial sciences are long dead since consultancy BS took over.
Longer than that. In WW2, factories increased hours to 60 to increase production. The workers were all on board with this. Production increased for a while, and then dipped below the 40 hour results.
Some experimentation showed that to get a sustained increase in production, the working hours would be increased for a time, and then brought back to 40, back and forth.
Personally, I'm well aware that when my tiredness exceeds a certain level, any programming work I do has to be undone (thank you, git!) and redone after I'm rested. What I do when I want to work, but am tired, is work on things that don't require much attention, like organizing my office, making backups, etc.