In Britain’s biggest four-day-week trial, 71 percent of employees said they felt less burnt out by the end. That figure, not anything about profit or output, is the one that stands out. Whether the shorter week would hurt productivity had a fairly predictable answer. What it would do to people did not.
We are writers and editors reading the research here, not psychologists, clinicians, or workplace-health specialists. What follows is our reading of one large pilot, not advice about your own work or wellbeing. The findings are self-reported, drawn from companies that chose to take part, so a pattern across the group is not a prescription for any individual reader or firm.
The trial: what 61 companies actually agreed to
From June to December 2022, 61 companies and around 2,900 employees switched to a shorter week on full pay. The deal was simple: 100 percent of pay for 80 percent of the hours, in exchange for keeping output at 100 percent. It was run by the campaign group 4 Day Week Global with the think tank Autonomy, and studied by researchers at Cambridge, Boston College, University College Dublin, Brussels and Salford.
There was no single template. Firms designed their own version, some closing on Fridays, others spreading days off across teams. And they had all volunteered. These were companies that already wanted to try, which matters for reading what came next.
Output held, but that was the expected finding
The business numbers held up. Among firms that supplied revenue data, takings rose by a marginal 1.4% on average over the trial. Broadly flat, which for a 20 percent cut in hours was the whole point.
Why output survived is perhaps less mysterious than it sounds. Brendan Burchell, who led the Cambridge research, said many workers “were much less inclined to kill time, and actively sought out technologies that improved their productivity”. Meetings shrank. Distractions got cut. With one less day, the work tended to find the four that remained.
Burchell put the headline finding plainly. Before the trial, he noted, “many questioned whether we would see an increase in productivity to offset the reduction in working time, but this is exactly what we found.” Hold this lightly: it is one volunteer pilot with no comparison group, not proof that a shorter week always lifts output. Within the trial, though, the productivity worry mostly dissolved.
The surprise was the people
The results that stood out most to us were about how people felt.
Alongside the 71% reporting reduced burnout, 39 percent said they were less stressed. Sick days fell by 65 percent. The number of staff leaving dropped by 57 percent. In interviews, Niamh Bridson Hubbard, one of the Cambridge researchers, said “it was common for employees to describe a significant reduction in stress. Many described being able to switch off or breathe more easily at home.”
Anyone who has spent the first day of a weekend recovering from the week, and only felt human by the second, will probably understand what a third day off might do.
One caution comes from a critic outside the study. Michael Leiter, an organisational psychologist not involved in the report, pointed out that “there’s a colloquial idea of burnout, which is that it’s being tired, and it’s being really frustrated with work.” The trial measured that everyday sense of the word, not the strict clinical version. Leiter thinks a four-day week probably reduces burnout on stricter measures too, but the distinction matters: the 71 percent is how people described feeling, not a diagnosis.
Time was another caution. As Scientific American noted, “the test period of six months was relatively short, so it remains unclear whether the favorable impact on well-being will persist in the long term.” What the researchers could claim was limited. Juliet Schor, a report co-author, said wellbeing “improved in the first three months, and that improvement was maintained. So we do know that in months three to six, we didn’t get regression.” It held steady over six months. Whether it lasts longer, the trial cannot say.
Why 89 percent kept it going
The strongest sign this was more than a novelty was what happened after the researchers stopped watching. At the trial’s close, 56 of the 61 firms, 92 percent, chose to keep the shorter week. A February 2024 follow-up found 54 of the 61 still running it a year on, with 31 having made it permanent.
A company that quietly reverts to five days once the study ends is telling you the trade did not work. Nearly nine in ten did the opposite. David Frayne, a Cambridge research associate, said the team felt “really encouraged by the results, which showed the many ways companies were turning the four-day week from a dream into realistic policy.” That is a researcher describing his own study, so take it as an interested view rather than a verdict. The retention figure is harder to spin. A striking 15 percent of employees said no amount of money would tempt them back to five days.
What the trial cannot tell us is whether any of this scales. The firms were volunteers, mostly office and knowledge work with flexible hours, the settings where a shorter week is easiest to arrange. Whether the same gains would survive on a hospital ward, in a warehouse, or in a call centre running fixed shifts is the question the pilot leaves open, and the one worth watching as bigger, less self-selected trials report back.
If the pace of your own work has started to feel unsustainable, a qualified counsellor or occupational-health professional is worth talking to, whatever your employer’s working pattern.
