More than 100 companies across the UK - among them a bank and marketing company - have permanently adopted a four-day working week since the COVID-19 pandemic.
Employees in the organisations work fewer hours, between 32 and 35 hours a week, but are certified by the 4 Day Week campaign group not to be paid any less despite working reduced hours.
In an effort to be attractive to prospective workers, boost productivity and employee wellbeing, employers are turning away from a traditional five-day week, believing it to be outdated.
According to the 4 Day Week group there are more than 2,600 employees in the more than 100 organisations, including around 450 staff each in Atom Bank and global marketing company Awin.
Awin CEO Adam Ross said that what initially was a trial measure has been "one of the most transformative initiatives we've seen in the history of the company".
"Over the course of the last year and a half, we have not only seen a tremendous increase in employee wellness and well-being but concurrently, our customer service and relations, as well as talent relations and retention also have benefited."
The 100 companies are separate to the 70 firms with 3,300 workers currently trialling a four-day week across the UK. The six-month pilot four-day week is to end next month, with results to be published in the new year.
New employers are to launch pilots in the new year, among them the Scottish government and South Cambridgeshire District Council.
Organisations across a range of sectors including manufacturing, architecture, technology, retail, housing, marketing, construction and events have been accredited in the last year and a half by the 4 Day Week Campaign.
Monday's 100 employer announcement demonstrates the success of the campaign, according to Joe Ryle, director of the 4 Day Week Campaign.
"This shows the momentum there is behind a four-day working week. We want to see a four-day week with no loss of pay become the normal way of working in this country by the end of the decade," he said.
"With many businesses struggling to afford 10% inflation pay rises, we're starting to see increasing evidence that a four-day week with no loss of pay is being offered as an alternative solution."
Monday also saw the launch of The Work Time Reduction Centre of Excellence in Canada.
The world-first has been set up, with UK-based company Curium Solutions, to support research on the impact and feasibility of reduced work time and to partner with companies to design and customise a work time reduction roadmap to suit business and employee needs.