Want to switch to a 4-day work week? Here's how to run a pilot, according to the author of a book on the subject.

• The idea of a four-day week is growing in popularity, and many companies are starting pilots.
• Joe Sanok is the author of a book about how to make the switch.

The idea of a four-day work week is growing in popularity.

Well-publicized trials in New Zealand, Iceland, and Japan showed that participants' wellbeing improved and they were more productive when they reduced their hours.

A trial is underway in Ireland, and governments in Spain and Scotland have pledged money to fund trials.

Author Joe Sanok has more experience with the four-day week than most. He first discovered its benefits while in college. It became a routine that he's experimented with while growing his own consultancy practice and in his role as a podcaster.

Sanok has collected his findings in his book "Thursday is the New Friday: How to Work Fewer Hours, Make More Money and Spend Time Doing What You Want."

"Right now, we have a window of opportunity where workers really can say this is the kind of job that I want, this is the hours that I want," Sanok said. Here are his tips for how to run your own four-day week experiment.

Before the trial

You'll have to first work out whether it's even possible to run a trial, and what that will look like.

Assuming that your manager or company has said yes, you should aim to run a trial with members of your team for no less than two to three months, Sanok said. This amount of time gives you data to work with.

The next stage is to define boundaries."Are we agreeing to no emails after 5 p.m.? Are we saying that we're not working at all on Friday?" Sanok said.

"Maybe you're an IT team and you need someone to cover your password management. There's going to be different things you need to work through to set the boundaries for that team," he added.

Next, you need to decide how you're going to measure success. You're not inventing something new, Sanok said. Therefore, it should be something that you're already judged on, be it sales, individual projects, or customer satisfaction.

During your experiment

Once you begin your trial, it's important to reflect back regularly to assess your progress. Sanok recommended doing so at the end of the first week.

This process is about being able to give your supervisor some qualitative evidence.

How did the boundaries you set work? Do they need to be adjusted? For example, some workers in Iceland's trial had to increase their hours after initially cutting them.

The second conversation to have is around the measures for success. How are you performing as a team against them? Is there anything you need to adjust?

Sanok recommended performing a 360 review that looks at all measures of how it works at the end of each month. Include graphs to show the data (if necessary). Also, speak to people involved in the trial to see how they've been spending their time to add narrative to your data, he said.

After your trial

At the end of the trial, write a report that brings together all of the 360 reviews. It should say what you've learned, state any benefits, and discuss what you'd change during a longer-term trial.

"Then your small group become leaders within the organisation to actually make systemic change with your supervisor's approval," Sanok said.

Be realistic

Ultimately, not everyone is able to work a four-day week. You can't always change company culture. There are also many forms it can take, and so doesn't necessarily mean a three-day weekend.

The key to making it work is focusing on productivity and ensuring that you're using your time as efficiently as possible. That is going to look very different for someone who is customer-facing compared with a data analyst, for example.