All work and no play makes Jack a dull boy, so the old proverb goes.
But does it also make Jack less productive, less efficient, unhappy and more stressed?
That's the view of a growing number of voices, including the UK's trade union body, the TUC. They want businesses to cut the standard working week from five days to just four.
The idea is that you keep your pay, but work fewer hours; a day off in the week to pursue your own interests or spend time with the family.
It may sound too good to be true, but late last year, one of the UK's leading charities, the Wellcome Trust, kicked off an organisation-wide consultation on whether to implement a four-day week.
"The exam question for us was, 'Could we improve both the productivity and well-being of Wellcome staff and at the same time improve the overall impact we have as a charity?'" says Ed Whiting, director of policy at the Wellcome Trust.
Businesses around the country took note. Several smaller companies have already made the shift to a four-day week, but for a large and respected non-profit organisation to go the same way would have set an important, perhaps even a game-changing, precedent for the UK's business landscape.
Except the Wellcome Trust decided against it.