More than 3,000 workers in the United Kingdom — from corporate desk jobs to retail employees — are getting an extra day off. This week, the UK launched the largest experiment of its kind: a four-day work week.

Organized by nonprofits 4 Day Week Global and 4 Day Week UK Campaign, thousands of workers across 70 companies will take part in the trial, which is based on the 100-80-100 rule (employees will work 80% of their time for 100% of their pay — given they still deliver 100% of their expected output).

Related: Is the 4-Day Work Week Better? Evidence Points to Yes.

“As we emerge from the pandemic, more and more companies are recognizing that the new frontier for competition is quality of life, and that reduced-hour, output-focused working is the vehicle to give them a competitive edge,” Joe O’Connor, chief executive of 4 Day Week Global, said in a statement.

The four-day work week has emerged as a new perk, stemming from a tight labor market and a ruthless battle for talent. But there could be more to the incentive than just attracting quality new hires.

“The four-day week is generally considered to be a triple dividend policy — helping employees, companies, and the climate,” said Juliet Schor, a sociology professor at Boston College and the experiment’s lead researcher, in a statement.

The standard 40-hour work week didn’t become commonplace until the Great Depression, when the government saw it as a solution to unemployment by rationing out work hours among more people. Up until then, working six days a week for more than 70 hours was customary. In fact, Henry Ford was one of the first leaders to speak up about the benefits of a reduced work week and noted that it increased productivity over a short period of time.

Experts in the UK are hoping this new change will become the new normal, and, perhaps, decrease worker burnout.

Related: This company switched to a 4 day work week and their business has been doing better

“What is most exciting about the pilot is that we have a wide range of sectors of economy from hospitality, retail, telecommunications, marketing and more participating,” Joe Ryle, campaign director for the UK arm of 4 Day Week, told CBS MoneyWatch. “There is a real mix, and we’re hoping it will show that the four-day workweek is possible across the economy in the longer term.”

Throughout the six-month trial, researchers will measure how the reduced workweek affects productivity and satisfaction among employees, as well as the impact on the environment and gender equality.

Related: How to Successfully Implement a 4-Day Workweek Even if You’re a Fast-Growing Startup