Yahoo Finance has a piece about Shake Shack’s experiment with 4-day, 10-hour days, which started earlier this year and appears to be expanding.

The better burger joint began testing a four-day workweek for its restaurant employees at several of its Las Vegas locations earlier this year. Shake Shack CEO Randy Garutti tells Yahoo Finance the test has since expanded to some of its restaurants on the West Coast.

While there is a cost component to a four-day workweek, Garutti says it’s the right thing to do for often overworked restaurant workers with families. And in this tight labor market, keeping employees healthy and happy is important to ensuring they don’t grab a gig elsewhere.

“I have been working in restaurants since I was 13, the restaurant business is super hard on families as our people work a lot of hours,” Garutti explains. “Why does it have to be that way is the question we have asked. We don’t know if it will work, it’s something we are testing at our West Coast shacks. We want to see if we can attract, retain and develop more people by changing how we think about how the restaurant business works.”

“I have had some new moms in the company come to me and say I have one less day of childcare. I have one less commute, this is amazing,” adds Garutti.

There are a number of world-class restaurants that have moved to 4-day weeks, and the movement has been slowly spreading from places whose reservations fill up in hours, to casual dining establishments. It’s good to see it moving to fast food, where some of the noisiest answers to “how to do we keep our workforce” have been along the lines of “screw them all, the robots are coming, bitch.”