A number of UK companies are set to move to a four-day working week, without any loss of income.
The two largest companies taking on the new structure are Atom Bank and global marketing firm Awin, each with around 450 UK staff.
Both companies have been accredited, meaning they have reduced hours for workers, rather than forcing them into longer but fewer days.
Speaking about what it has been like to transition to the four-day week, Adam Ross, Awin’s chief executive said it had been 'one of the most transformative initiatives we’ve seen in the history of the company'.
He added: “Over the course of the last year and a half, we have not only seen a tremendous increase in employee wellness and wellbeing but concurrently, our customer service and relations, as well as talent relations and retention also have benefited.”
The 4 Day Week Campaign is hoping that the 100 companies will pave the way for other employers in the UK, with supporters claiming that the five-day week is a 'hangover' from an old economic age.
They argue that those who take on the four-day working week would increase productivity and achieve the same output in fewer hours.
Those who have already taken on the new structure say it's been a great way of retaining employees, as well as attracting new staff to the company.
The campaign group - alongside researchers at the Universities of Oxford and Cambridge, Boston College and thinktank Autonomy - is currently running the world's largest pilot for the four-day week for around 70 companies, employing 3,300 workers.
Companies taking part were asked in September (mid-way through) how the trial was going, and 88 per cent said it was going 'well'.
Meanwhile 95 per cent said productivity had either remained the same or improved.
Joe Ryle, UK director for the campaign, said there's an increased momentum for the four-day week pattern.
“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 so we are aiming to sign up many more companies over the next few years,” 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.”