In June 2022, 61 UK organizations embarked on a six-month trial of a four-day working week. Employees would have a 20 percent cut to their working hours with no change in salary, while companies kept a close eye on productivity. Now, the results of the trial show how employee wellbeing was significantly enhanced, retention went up, and sickness decreased – and all with no damage to the bottom line.

Non-profit 4 Day Week Global led the trial in conjunction with the UK’s 4 Day Week Campaign, and the research was conducted by a team of scientists from the University of Cambridge, Boston College and the think tank Autonomy. Around 2,900 employees were involved across a huge range of industries, from IT and financial services to healthcare, and even a fish and chip shop.

Things were looking good even at the halfway point of the trial, with many companies reporting positive interim results. Similarly optimistic reports were released after a comparable pilot program in North America and the Republic of Ireland. However, the full results of the UK trial have been eagerly awaited, as both the largest to date and the first to incorporate in-depth research interviews with employees and CEOs.

“The method of this pilot allowed our researchers to go beyond surveys and look in detail at how the companies were making it work on the ground,” said Dr David Frayne of the University of Cambridge, in a statement.

Compared to the start of the trial period, 71 percent of employees reported lower levels of “burnout” under the 4-day week, and 39 percent said they were less stressed. Staff also reported improved work-life balance, with 62 percent finding it easier to balance work with socializing, and 60 percent feeling better able to juggle work and caring responsibilities.

This reported improvement in wellbeing was borne out in the results for employee sickness and retention, too: participating companies reported 65 percent fewer sick days and a 57 percent drop in staff leaving the workforce.

On top of all that, company revenue actually slightly increased during the trial, by an average of 1.4 percent, so the changes apparently did no harm to productivity.

It’s perhaps unsurprising that 92 percent of the participating companies have indicated a willingness to continue the program, with 18 of them already confirming that the changes have been made permanent.

“We feel really encouraged by the results, which showed the many ways companies were turning the four-day week from a dream into realistic policy, with multiple benefits,” said Frayne.

“Before the trial, many questioned whether we would see an increase in productivity to offset the reduction in working time – but this is exactly what we found,” added colleague Professor Brendan Burchell, who led the work at the University of Cambridge.

Companies had flexibility in how they implemented the reduction in working hours – one restaurant ensured that their working weeks averaged out at 32 hours over the year by maintaining longer opening hours in summer and much shorter hours in winter. Managers also took steps to maximize employees’ time over a shorter week, such as trimming down meetings and improving end-of-day handover processes.

“When we ask employers, a lot of them are convinced the four-day week is going to happen,” said Burchell. “It has been uplifting for me personally, just talking to so many upbeat people over the last six months. A four-day week means a better working life and family life for so many people.”

A full report on the trial can be accessed via 4 Day Week Global.