<i>It’s been about a century since the economist John Maynard Keynes first touted the six-hour workday, predicting that by 2030 only extreme workaholics would work more than 15 hours a week.</i> Still waiting for flying cars too.
Creative workers as a group would definitely do something about this if they were concerned so much.<p>Software developers mostly work noon to 8PM where I live. Go figure.
Constraints like time are a forcing function. They aren't necessarily good or bad. You could argue many creations wouldn't have happened had someone not been stuck in a job they created something to liberate themselves from.
The linked study about when to sleep is on ReasearchGate and can be found via your search engine of preference.<p>(Not linking directly because I am not sure if that page is legal, Taylor & Francis Online charges for access).