Companies from Microsoft to Shake Shack have experimented with a shorter, 4-day workweek - and most of the time it's worked really well

During the summer months, the staff at project management software company Basecamp gets to work four days per week, resulting in a 32-hour workweek. The policy is in effect from May 1 through August 31, although new employees may be required to complete a training period.

The 32-hour workweek helps employees focus on the tasks that are most important to their job, Chase Clemons, Basecamp's customer support team lead, said in an interview with CNBC.

"Thirty-two hours forces us to prioritize what we work on," Clemons said to the outlet. "It's not about working faster, but rather working smarter."

Uniqlo parent company Fast Retailing announced in 2015 that the Japanese clothing company would allow one-fifth of its employees to take a four-day workweek. Workers still have to put in 40 hours per week, however.

Fast Retailing offered the perk to full-time store workers with the goal of preventing employees from switching to part-time to achieve a better work-life balance, Bloomberg reported when the policy was introduced.

Andrew Barnes, founder of New Zealand-based estate planning service provider Perpetual Guardian, may be the biggest supporter of the four-day work week yet.

His company ran a trial in March 2018 that involved giving all 240 of its staff across New Zealand one paid day off per week. Employees worked 30 hour weeks but were paid the same and were required to produce the same amount of work.

After the trial, the company found that team engagement had increased noticeably, while work-life balance and stress decreased. The company has been implementing the policy on a long-term opt-in basis since last November.

Barnes has been a vocal advocate of the four-day workweek ever since, and even established a nonprofit organization to support the idea.

Not all trial runs of the four-day workweek have proven successful.

Treehouse, a company that offers virtual classes for learning how to code, tried the four-day workweek in 2015. But it nixed the policy in 2016, company CEO Ryan Carson said when speaking during GrowthLab Live in 2018.

"It created this lack of worth ethic in me that was fundamentally detrimental to the business and to our mission," Carson said last year. "It actually was a terrible thing."

Software company Wildbit also ran a trial in 2017 that involved taking Fridays off.

"We're challenging ourselves that by limiting our time, we'll produce more thoughtful and important work than when we had 40 hours to get it all done," cofounder and CEO Natalie Nagele wrote in 2017.

Since then, the company has experimented with the format to adjust for busier periods of the year. It eventually moved to giving some support team members Mondays off instead of Fridays, and has considered implementing shorter workdays instead of full days off, according to Fast Company.

Nagele also told the outlet that the company launched more features in its first year of implementing the four-day workweek compared to the previous year. The system also helped employees avoid distractions and focus on priority tasks.