this has always been a lie*. A good life only needs 75 GJ per person** to achieve what Ian MacHarg calls creative fitting - resulting in health***. So why work a day more? I never have. Always max 3 days a week for any boss. You'd be surprised what those life-long 4 free days a week can bring you....
* https://www.youtube.com/watch?v=8l5fRI-YnG0&t=5s
**https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.3978