For workers, finally getting a three-day weekend is a blessing. Having a few days off has led to increased health and happiness at the job. Now, certain European companies are trying to make a four-day workweek a permanent thing.

Some mixed feelings

How exactly would this play out? Unlike a three-day weekend, workers will be paid for five workdays instead of four. The number of hours will diminish because of this shift. Instead of 36 hours, employees will have only 26 hours. While it intrigues many European companies, research foundation Wellcome Trust had the opposite feeling. In April, they revealed plans to give workers Fridays off with pay, but that was scrapped. “After extensive internal consultation on whether we should trial the four-day week, we have concluded that it is too operationally complex to implement,” Wellcome Trust director of policy Ed Whiting told The Guardian.

It works in New Zealand

Last year, New Zealand financial services firm Perpetual Guardian tested out a four-day workweek. In a published study, workers were more productive at their job. Now, the company made four day work weeks permanent. Workers have the option to show up for five days for some extra cash. “For us, this is about our company getting improved productivity from greater workplace efficiencies… there’s no downside for us. The right attitude is a requirement to make it work – everyone has to be committed and take it seriously for us to create a viable long-term model for our business,” Perpetual Guardian founder Andrew Barnes told Metro. Barnes got the idea after hearing employees were only productive for three hours at work.

Some disadvantages to this plan

While productivity and overall happiness are positive, there are drawbacks to this work schedule. Being able to find proper childcare can be a challenge. Most childcare places in the country close around 5 p.m. Under a four-day workweek, the schedule may have people working beyond that time.

There’s also the problem of contacting employees on their day off. Many people often shut their phones off to avoid work emails coming their way. “In the case of an exempt employee who has an alternate schedule while others work the traditional Monday-Friday schedule, that person may feel pressure to call into meetings or respond to messages on her day off. This is not fair but you need to assess whether the alternative schedule is adversely affecting the employee’s team,” journalist Suzanne Lucas told The Balance.

Another problem involves vacation time. In New Zealand, they base vacation time on the number of hours in the office. With lesser time in the office, they can expect the same with their time off. Sick days will take a hit as well. Employees would have to work a bit more in order to offset the time lost.

Can it be done?

Before implementing a four-day workweek, employers must wonder if it’s worth it. Would their business suffer without having the right amount of people in the office at once? San Francisco software company Monograph stated this plan worked with their employees. “Mid-week is great to reset your brain while working on hard problems, so Thursday we can get back at it and have the mental strength to push forward. But largely the biggest benefit is getting a chance to work on side projects! It’s part of our culture at Monograph to have your own thing,” Monograph co-founder Moe Amaya told Huffington Post. Monograph has only eight employees in employment.

Other smaller companies might not have the same positive outcome. Major companies could still struggle to make this work. With more on their plate, they’ll need as many employees as possible on the floor. This isn’t stopping companies around the world from testing it out, though. The U.K.’s Trades Union Congress has been lobbying for a four-day workweek. They’re hoping it’ll become permanent by the end of the century. If this becomes a growing trend, it might become law worldwide in a few years.