At one of his first jobs after college, Ryan Carson was a software developer who was asked to stay overnight to finish a project.

"We ended up working 48 straight hours. I remember catching a few minutes' sleep on the floor," he said.

That experience, all too common at startups, gave him a different idea: What if companies could prevent burnout (and reward their employees) by limiting the number of hours they worked?

So in 2010, he gave it a shot. Treehouse, located in Portland, Ore., develops online courses in website-building, code writing and mobile apps. The firm, which Carson cofounded, has a second office in Orlando, Fla., and about half of its 75 employees work remotely.

While purposefully avoiding San Francisco, Treehouse offers plenty of Silicon-Valley-style perks. The biggest: Every weekend starts on Thursday night.

And that doesn't mean Monday through Thursday are 10-hour days. Carson says they still maintain a normal schedule throughout the week.

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It's proven to be a powerful recruiting tool.

"At first, we didn't tell candidates about the four-day week [right away] because we really wanted people who were passionate about our mission of low-cost online education," Carson recalled. "But we started mentioning the short week up front when we realized what an advantage it is in attracting top talent."

One Treehouse developer regularly gets job offers from Facebook and Google, Carson said, but "so far, his answer has always been, 'You guys working a four-day week yet?'"

There are plenty of advantages to the schedule, but it also presents some obvious challenges, which Carson has had to navigate.

"I'm very selective about the projects I take on," he said. "The key is to focus on what you want to get done. Carve out blocks of time where you can concentrate on one thing at a time, and cut out distractions like unnecessary meetings."

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Email is another time suck Carson avoids. Instead, Treehouse staffers use a free service called Hipchat that allows businesses to set up chat rooms. Rather than emailing colleagues or interrupting them mid-project, employees post questions and comments that others respond to "when they get around to it," Carson said. Treehouse also designed an online tool called Flow, where people post daily updates on specific projects.

If a four-day week were easy, everyone would be doing it, and Carson conceded that it does have drawbacks.

"The biggest one is that it's pretty hectic," he said. "There's no downtime. With a four-day week, every hour counts. It can be stressful."

And as a business owner, Carson said, "I get frustrated sometimes, thinking we could do more and grow faster if we had that fifth day."

Even so, he's committed to keeping the four-day week and, financially, Treehouse has done fine without Fridays. Carson said the company was profitable almost immediately, and revenues have tripled to about $10 million in the past three years.

Venture capitalists, including big names like Kevin Rose and Reid Hoffman, don't seem at all put off by Treehouse's abbreviated schedule. So far, they've invested $11.5 million.