Four-Day Workweek Experiments: What Studies Reveal

The idea of a four day workweek keeps moving from coffee-shop chatter to boardroom pilots. Four day workweek experiments promise higher productivity, happier staff and fewer sick days—but do they deliver? I’ve read the reports, followed the pilots and spoken to managers running real trials. This article walks through the strongest experiments to date, what worked (and what didn’t), and a practical checklist for running your own pilot.

Why businesses are testing a four-day workweek

Companies are under pressure to attract talent and cut churn. At the same time, workers want better work-life balance. The four-day workweek is being tested as a potential win-win: maintain or boost output while giving staff one extra day off.

What companies hope to achieve

• Higher productivity per hour rather than more hours
• Lower burnout and improved employee wellbeing
• Better talent attraction and retention
• Lower operational costs (sometimes)

Different models used in experiments

Not every trial is the same. From what I’ve seen, three models dominate:

• Reduced hours, same pay — e.g., 32 hours a week for the same salary.
• Compressed hours — longer workdays packed into four days (still full-time hours).
• Flexible model — employees choose their extra day off, with core overlap hours.

Quick comparison

Notable experiments and what they showed

Some experiments are small, some national. Taken together, they give useful signals.

Microsoft Japan (2019)

Microsoft Japan ran a bold trial in 2019, giving employees five consecutive Fridays off. The firm reported a 40% rise in productivity and lower meeting time. That experiment got a lot of press and sparked broader interest—though critics warned results may not generalize across industries.

Read the Microsoft summary on Microsoft’s site.

Icelandic trials (2015–2019)

Iceland carried out large-scale trials with municipal and national employees. Independent evaluators reported productivity stayed the same or improved, while wellbeing rose substantially. The trial led to shorter hours for many workers across the country.

Overview and evaluation details are summarized on the Icelandic study pages and coverage like Wikipedia’s entry on the topic: Four-day week — Wikipedia.

UK 4 Day Week Pilot (2022)

One of the most-cited recent pilots was coordinated by 4 Day Week Global alongside academic partners. The trial involved dozens of companies and reported positive results: most companies met productivity targets while staff wellbeing and retention improved. Coverage and analysis of the pilot appeared widely in outlets like the BBC: BBC coverage of the 4-day week trials.

Common benefits seen in experiments

• Productivity gains in many knowledge-sector pilots—often due to fewer, shorter meetings and more focused work time.
• Improved wellbeing — lower stress and improved work–life balance reported across trials.
• Lower staff turnover and improved recruitment metrics in several pilots.
• Potential environmental benefits — fewer commutes can reduce emissions.

Practical challenges and limitations

• Not suitable for all roles — shift-based, frontline services, and some client-facing jobs need careful coverage planning.
• Risk of work getting crammed into fewer hours — leading to hidden overtime.
• Scheduling complexity when employees take different days off.
• Short-term hype vs long-term sustainability: some organizations saw initial gains that later required process fixes.

How to design a four-day workweek experiment (a checklist)

Thinking of running a pilot? Here’s a pragmatic plan that echoes successful trials.

• Define objectives: productivity, wellbeing, retention—pick measurable KPIs.
• Choose a model: reduced hours, compressed, or flexible.
• Set duration: 3–6 months is typical for meaningful data.
• Communicate early and often: clients, vendors and staff need clarity on coverage.
• Measure baseline metrics for at least a month before the pilot.
• Use simple productivity metrics: output, lead time, customer satisfaction and time spent in meetings.
• Plan for experiment governance: how to handle exceptions, urgent work and feedback loops.
• Run retrospectives regularly and be ready to iterate.

Suggested KPIs to track

• Task completion rate and lead times
• Customer satisfaction (NPS or CSAT)
• Sick days and turnover rate
• Employee engagement survey results
• Meeting hours per person

Measuring success — what counts

Success is more than output per hour. You want sustained productivity, improved wellbeing and manageable operations. If productivity holds and wellbeing improves without added costs or broken SLAs, that’s a win.

Real-world tips from managers who ran pilots

• Cut recurring meetings by default; require agendas and outcomes.
• Empower teams to decide which tasks stay and which get deprioritized.
• Set core overlap hours to preserve collaboration windows.
• Track data continuously and be transparent with teams about results.

Is a four-day workweek right for your company?

It depends. If you’re in a knowledge-based environment and you struggle with meetings, distractions and burnout, it’s worth piloting. If you’re in continuous 24/7 operations, a full switch may be harder but hybrid models can work.

Next steps you can take this month

• Run a one-team pilot for 8–12 weeks with clear KPIs.
• Survey employees about priorities and likely trade-offs.
• Simplify processes and reduce meeting load before changing schedules.

For a broader historical and global overview see the Wikipedia entry on the topic: Four-day week. For details on coordinated pilots and research, the 4 Day Week Global site has primary resources: 4 Day Week Global. For recent journalism and a digestible summary of pilot results see the BBC’s reporting on the UK trials.

Short summary

Experiments suggest the four-day workweek can work—especially in knowledge sectors—if you design the pilot carefully, measure the right metrics and reduce waste (meetings, unclear priorities). It’s not a silver bullet, but worth testing where flexibility and innovation matter.