The merits of a four-day workweek have been proven repeatedly. Software company 37signals switches to a four-day workweek from May through October, and only asks employees to work 32 hours a week during that time. CEO Jason Fried wrote in The New York Times that employees get more productive during those months.

“When there’s less time to work, you waste less time,” Fried told the paper. “When you have a compressed workweek, you tend to focus on what’s important. Constraining time encourages quality time.”

Utah experimented with a four-day workweek for state workers, but switched back to a traditional week in 2011. Employees loved the four-day stretches, and spent their days off volunteering or working second jobs, The Associated Press reports. Employees had fewer conflicts with work and home and saved money on gas. There was just one problem: Residents complained because some state services weren’t available on Fridays.