The results of the world's biggest ever four-day working week pilot which took place in the UK have been revealed with almost every company that took part deciding to continue with a four-day week, with no loss of pay for workers.

Of the 61 companies that participated, at least 56 are continuing with the four-day week, with 18 saying the policy is a permanent change.

The vast majority of companies said business performance and productivity was maintained while employees reported lower levels of burnout with more time to manage childcare and other commitments.

The findings are published in a report by the think tank Autonomy and leading academics at the University of Cambridge and Boston College in the US.

David Frayne, a research associate at University of Cambridge, said: “We think there is a lot here that ought to motivate other companies and industries to give it a try.

"The method of this pilot allowed our researchers to look in detail at how the companies were making things work on the ground.

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

Good for staff

Key findings show levels of anxiety, fatigue and sleep issues decreased for employees while mental and physical health improved.

Measures of work-life balance improved. Respondents found it easier to balance their work with both family and social commitments, and were more satisfied with their household finances, relationships and how their time was being managed.

Do businesses suffer?

For businesses, companies’ revenue stayed broadly the same, rising by 1.4% on average.

In terms of retention, there was a substantial decline (57%) in the likelihood that an employee would quit and there was a 65% reduction in the number of sick days.

READ MORE: I'm a four-day week boss, this is how we did it and what I've learned along the way

Organisations that took part in the pilot trialled a four-day 32-hour week with no loss of pay for employees.

The firms were allowed to design their own four-day week to suit its particular industry, organisational challenges, departmental structures and work culture. Some trialled a classic Friday off models, to staggered teams, annualised hours for seasonal businesses and structures based on conditional performance indicators being met.

What about the ones that said no?

Of the five businesses who are not continuing with the four-day week, two have opted to extend their trials of shorter working hours (one started late and is still in the pilot phase and the other is experimenting with a four-and-a-half day week).

Three others have paused the four-day week in their organisation for the time being.

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Around 2,900 employees took part in the six-month trial overall, which kicked off at the beginning of June 2022 and was run by 4 Day Week Global in partnership with Autonomy, the 4 Day Week Campaign, and researchers at University of Cambridge and Boston College.

The four-day week was a game changer for us

Among the organisations taking part were the Citizens Advice, Gateshead.

Paul Oliver, 48, Chief Operating Officer said the charity was keen on the idea of a four-day week as a way of improving job recruitment and retention.

He said: “We wanted a way of delivering our services that ensured our clients were getting the best level of support from well rested and more productive staff and the four-day week was a game changer for us in that respect.

“It feels like it's really making a difference in so many crucial ways. Staff are getting more work done in less time and overall working more efficiently and effectively."

Another was Flatpack Projects, the Birmingham-based mobile arts organisation behind the city's annual Flatpack film and media festival.

Director Ian Francis said that inclusivity and staff wellbeing were at the heart of the decision to trial a 32-hour week.

"We wanted to explore ways of offering balance to our employees and remove barriers for those who might find a typical 40-hour week challenging.

"Everyone in the team felt their time management and ability to prioritise had improved and, while the six months weren't without challenges, we will be continuing the 32-hour week beyond the trial period."

Tyler Grange was among those taking part - managing director Simon Ursell said: We’re able to demonstrate, first-hand, how challenges of the four-day working week can be overcome and the many holistic benefits that can be enjoyed as a result. Employers really shouldn’t be afraid of it – they should embrace it."

What happens next?

Academics and campaigners are presenting the results to MPs in the House of Commons today.

Joe Ryle, Director of the 4 Day Week Campaign, said the time has now come to begin rolling it out across the country.

He said: “This is a major breakthrough moment for the movement towards a four-day working week.

“Across a wide variety of different sectors of the economy, these incredible results show that the four-day week with no loss of pay really works."

Charlotte Lockhart, 4 Day Week Global Co-Founder and Managing Director, said that the findings largely mirror the outcomes from earlier trials in Ireland and the US, further strengthening the arguments for a four-day week.

She said the shorter working week brought different benefits, depending on industry.

She said: "These results, combined with our previous research demonstrate that non-profit and professional service employees had a larger increase in time spent exercising, while the small group of construction/manufacturing workers had the biggest reduction in burnout and sleep problems. Certainly something to explore further in future pilots.”

However, employment solicitor Charlotte Morris, Associate Solicitor at esp Law urged caution.

She said: “Many of the reported benefits of the four-day working week are only going to be truly identifiable long-term so it’s interesting to finally see results from a trial done at some length. Arguably though, given the prolonged period of time we work for, from leaving education to retirement age for most, a six-month trial is still not long enough to truly measure the impact a shorter working week will have.

“Businesses may be able to sustain it for 12 months but not for five or ten years, and, on the flip side, the positive impact that improved employee wellbeing can have will be best seen when you can compare staff absence, sickness rates and burnout over years. Therefore, results must be taken with a degree of caution and they may not be sufficient enough for us to see a seismic shift to a four-day week by businesses."