The pilot involved 17 companies and almost 1,000 workers, and ran for six months from November, organised by the 4 Day Week Foundation in the UK and monitored by researchers at Boston College in the US.

The companies taking part all reduced their working hours with no loss of pay for employees, with 12 of the participating organisations opting for a four-day week and five opted for a nine-day fortnight. 

The pilot found that organisations were able to maintain service levels and key performance indicators while observing several benefits for employee well-being.

In addition, 62% of workers registered a reduction in how often they experienced burnout, 41% of participants had an improvement in their mental health, and 45% felt more satisfied with life.

More than half ( 54%) of employees registered an increase in ‘working smart’, and every company decided to keep the shorter working schedule at the end of the trial.

Some of the businesses taking part reported a reduction in resignations and number of sick days taken, an increase in customer satisfaction and one company increased their revenue by 129%. 

The last major UK pilot in 2022 involved 61 companies and nearly 3,000 workers, with 92% of companies deciding to continue with the four-day week afterwards. 

The 4 Day Week Foundation said the government should create a Working Time Council to bring together business leaders, industry leaders and trade unions to coordinate on policy and implementation of a shorter working week.

The organisation is also recruiting organisations for another National Four-Day Week Trial that is due to get underway in November this year. 

Joe Ryle, campaign director at the 4 Day Week Foundation, said: “With greater knowledge, expertise and experience of what it takes to successfully implement a four-day week, we’re really pleased to see such a high success rate. 

“People are happier, businesses are thriving, and there’s no turning back. We’ve proved it again and again: a four-day week works and should now be implemented more widely across the economy.”