Young adults are throwing their support behind calls for a four-day workweek.

A new national survey from CNBC/Generation Lab of 1,033 people aged 18 to 34 found that an overwhelming 81% of respondents believe a four-day workweek would boost their company's productivity, while 19% said productivity would decline.

Those results from the "Youth & Money in the USA" survey come amid discussions around the potential benefits of switching from the standard five-day U.S. workweek to a four-day cadence without a pay cut.

Some companies have begun testing the arrangement, and say it has mitigated employee burnout and strengthened business performance.

Exos, a U.S. coaching company that trains top athletes and leads corporate wellness programs, recently reported results from the first six months of an ongoing four-day workweek experiment. The company said the shortened workweek increased efficiency along with revenue and retention.

Other four-day workweek trials have shown similar gains.

Although respondents to the CNBC/Generation Lab survey largely agreed on workweek length, they were less unified when asked about work setting. A 60% majority said they do their best work in the office, while the other 40% said they do so at home.

Beyond the workplace, the reduced workweek also has its advocates in Congress. Sen. Bernie Sanders, I-Vt., introduced a bill in March that would bring the standard workweek down to 32 hours without a change to pay. The Senate bill is a companion to one reintroduced in the House of Representatives in March 2023 by Rep. Mark Takano, D-Calif., after it failed to advance upon its first introduction in 2021.

Some prominent business leaders, too, have chimed into the conversation with their predictions for the workweek's future.

IAC and Expedia chairman Barry Diller said he thinks companies will adopt a policy of four days in office followed by a flexible Friday.

"Not necessarily a four-day workweek, but four days in the office, and Fridays you can work from home or work at your own schedule," he said on CNBC's "Squawk Box" in April. "I think that is going to be the sensible evolution of all this, but it has to be standardized."

New York Mets owner and billionaire financier Steven Cohen believes a widespread four-day workweek is on the horizon, citing the rise of artificial intelligence and generally lower productivity on Fridays. That thinking partly motivated his 2023 investment in golf startup league TGL.

"I think I would have done the golf investment anyway because I think there's a longer-term thought, but my belief is a four-day workweek is coming," Cohen told "Squawk Box" in April. 

Want to make extra money outside of your day job? Sign up for CNBC's new online course How to Earn Passive Income Online to learn about common passive income streams, tips to get started and real-life success stories. CNBC Make It readers can use special discount code CNBC40 to get 40% off through 8/15/24.

Plus, sign up for CNBC Make It's newsletter to get tips and tricks for success at work, with money and in life.