Thousands of Brits are being moved to a four-day working week without losing any of their pay.
Around 2,600 workers from 100 companies, including Atom Bank and global marketing company Awin, will be making the shift in a bid to boost productivity.
It comes as a number of businesses across the UK, including marketing firm Fuel, digital marketing company Reboot Online and chippy Plattens Fish and Chips in Norfolk have decided to introduce a shorter working week for their employees.
Those who advocate the four-day working week say it would allow companies to produce the same output in less hours.
The biggest companies in the UK to sign up are Atom Bank and global marketing company Awin, each employing around 450 staff.
A campaign in the UK - called the 4 Day Week Campaign - has been trialling the new system with more than 3,300 workers across 70 companies for a total of six months.
A survey conducted mid-trial found that 88% of workers agreed that the four-day week was working "well" for their business.
It revealed 15% of workers said that productivity had dramatically increased, while the remaining 95% recorded no change, or only a "slight improvement".
Awin's chief executive, Adam Ross, said the change was “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 wellbeing but concurrently, our customer service and relations, as well as talent relations and retention also have benefited”, he added.
But some companies said the trial brought up some issues, as they struggled to organise rotas, leaving staff confused.
Researchers at the Universities of Oxford and Cambridge, Boston college and thinktank Autonomy are also taking part in the scheme.
Samantha Losey, boss of communications firm Unity, told The Telegraph last month: "It's more likely that we won't carry on now.
"One of the things that has struck me is whether or not we are a mature enough business to be able to handle the four-day week.
"The rest of the world not doing four-day weeks makes it challenging. We agreed we'd go all the way through the pilot, but I'm questioning whether this is the right thing for us long-term. It's been bumpy for sure.
"Ultimately, the outcomes we're experiencing, such as better, higher, and a positive team culture shift are reassuring that the bumps in the road are exponentially worth it."
It comes as a trial in France found employees were producing the same amount of work in just four days as they were in five - meaning companies were paying extra for unused hours.
