On paper, it was just a calendar shift—Fridays disappearing from the workweek like a vanishing weekday. But for nearly 3,000 employees across six countries, it felt more like a recalibration of modern life.
They were participants in a bold, global experiment: a four-day workweek with no cut in pay and no expectation to squeeze five days into four. For six months, researchers followed them, measuring stress, sleep, satisfaction, even how often they exercised. What they uncovered wasn’t just a temporary lift in mood or a modest workplace tweak. It was something more fundamental: a reengineering of the relationship between time, labor, and well-being.
This ambitious effort aimed to answer a simple question: can we work less without doing less?
The answer, it turns out, is yes.
Six Nations Test the Four-Day Week
Researchers led by Wen Fan of Boston College and Juliet Schor of Boston College and Orla Kelly of University College Dublin tracked 2,896 employees across 141 companies in Australia, Canada, Ireland, New Zealand, the United Kingdom, and the United States. The study, published in Nature Human Behaviour, evaluated the effects of reducing full-time schedules from five to four days a week without reducing pay.
The results were unequivocal.
Employees who switched to a four-day week reported lower burnout, better sleep, less fatigue, and improved physical and mental health. Job satisfaction climbed. And surprisingly, they didn’t feel more pressured to cram five days of work into four. Quite the opposite: many said their ability to perform actually improved.
“A lot of people are worried about a process called job intensification,” Fan told New Scientist. “What we found is the opposite: once workers are able to [reduce hours], they feel better about themselves and this helps their well-being.”
How the Trial Worked
The companies volunteered for the trial through the non-profit 4 Day Week Global. Each had eight weeks to restructure workflows before the six-month program began. This typically involves streamlining inefficient practices like endless Zoom calls. Employees were surveyed before and after the trial with questions like, “Does your work frustrate you?” and “How would you rate your mental health?”
By the end of the trial, the average number of hours worked each week dropped by more than five—from 39.2 to 34 hours. In contrast, control companies that didn’t participate saw no significant changes in work hours or employee well-being.
Well-being gains were not limited to one group. The results held true across different ages, genders, and work settings—whether remote or in-office. However, supervisors experienced the largest improvements in well-being.
And the effects lasted. When researchers followed up a year later, workers still reported higher well-being and fewer hours worked.
What Actually Improved?
The biggest change was in burnout. Among trial participants, feelings of exhaustion due to work fell sharply—from 2.83 to 2.38 on a 5-point scale. Job satisfaction rose by half a point. Mental health improved modestly, and physical health saw smaller, yet statistically significant, gains.
Some of the changes had a biological basis. Employees slept better and felt less fatigued. They exercised more frequently. And those who cut the most hours—8 or more per week—reported the most dramatic benefits.
These well-being boosts weren’t limited to personal lifestyle changes. They stemmed in part from a greater sense of work “ability”—the feeling of being effective at one’s job. As the study authors wrote, “the work reorganisation process opened up by 4-day weeks has led to profound changes in the job experience itself.”
The Question of Productivity
One of the most persistent concerns about a shorter workweek is whether companies can maintain output. The new study didn’t directly measure productivity at the organizational level. Still, more than 90% of participating companies opted to continue the four-day schedule after the trial ended—a vote of confidence that suggests output didn’t suffer.
“When people are more well rested, they make fewer mistakes and work more intensely,” Pedro Gomes, an economist at Birkbeck University of London, told Nature. But he cautioned that we still need to see more analysis of the impacts on productivity.
A prior 2022 trial in the UK involving roughly 2,900 employees found that while about 50% of employers reported improved productivity, 55% of workers said their ability to work improved—and an impressive 92% of firms opted to keep the four-day schedule after the study ended.
Why it Works
The researchers found that three factors played the biggest role in mediating the benefits: improved self-reported work ability, fewer sleep problems, and reduced fatigue. While job satisfaction and mental health improved across the board, physical health changes were more gradual.
Interestingly, individual-level changes mattered more than company-wide ones. Employees who personally reduced their hours reaped greater well-being benefits than those in companies that made cuts at the organizational level without adjusting individual schedules.
And these weren’t just minor gains. Employees who reduced their weekly hours by eight or more reported noticeably better outcomes. They felt significantly less burned out, more satisfied with their jobs, and experienced clear improvements in their mental health.
“Even with the extensive set of mediators, changes in work hours remain significant predictors of well-being, especially for burnout and job satisfaction,” the authors noted in the study.
There are caveats, however. The companies opted in voluntarily, which means they may already have been more open to flexible work or employee well-being initiatives. Most firms were small and based in English-speaking countries.
And the outcomes were self-reported, raising the possibility that employees exaggerated benefits in hopes of keeping their long weekends.
“We view our findings as a call for a randomized study on work time reductions, possibly through government-sponsored trials,” the authors wrote.
Still, the consistency of the results across geographies and industries is striking. Whether in a Canadian tech startup or a New Zealand nonprofit, the pattern was the same: fewer hours, better lives.
Time for a Change?
For decades, the five-day work week has been seen as immutable. It was Henry Ford who helped usher it in, reducing factory schedules from six days to five nearly a century ago. Now, that once-radical idea is itself being challenged.
As conversations about burnout, work-life balance, and mental health continue to gain traction, this study may help nudge the conversation away from asking if we can afford a shorter workweek—and toward asking why we haven’t done it sooner.
