Microsoft Japan’s Four-Day Workweek Experiment: A Closer Look
In August 2019, Microsoft Japan implemented a bold initiative by closing its offices every Friday, granting approximately 2,300 employees five days of special paid leave. Remarkably, at the end of the month, the company reported that sales per employee were 39.9% higher than in August 2018, despite a working calendar that was 25.4% shorter. This result quickly became emblematic of the potential benefits of a four-day workweek producing nearly 40% more productivity. However, Microsoft later tempered this claim, clarifying that the impressive figure was not solely due to the reduced workweek but resulted from multiple contributing factors.
The Context and Design of the Work-Life Choice Challenge
Microsoft Japan’s program, dubbed the Work-Life Choice Challenge Summer 2019, transformed all five Fridays in August into paid holidays without deducting from annual leave. While the offices were closed on these days, exceptions were made for employees whose duties required customer service or other business needs; these employees could take their special leave on alternative days before the end of September. This approach allowed Microsoft Japan to conduct a broad, though not absolute, company-wide experiment.
The initiative aligned with Japan’s broader national efforts to tackle the country’s notorious long working hours, which have been linked to health risks and overwork-related deaths. Since April 2019, Japan’s work-style reforms have aimed to improve work-life balance, supported by the Ministry of Health’s dedicated programs to prevent overwork illnesses. Microsoft Japan’s goal was to encourage employees to work smarter, rest better, and learn from the process.
Interpreting the 39.9% Productivity Increase
Microsoft defined labor productivity as sales divided by employee headcount. The reported 39.9% increase compared August 2019 to August 2018, not a direct measurement of output per hour or task completion. Sales figures can fluctuate for many reasons, including contract timing, product cycles, market conditions, and pricing changes. Importantly, the company did not run a simultaneous control group under identical conditions, limiting the ability to attribute the productivity boost solely to the four-day workweek.
On November 8, 2019, Microsoft Japan issued a clarification emphasizing that while the sales increase figure was accurate, it was not caused by the reduced working days alone. This candid correction is crucial—it draws a line between an intriguing correlation and an unsupported causal claim. The experiment’s real contribution was prompting a reevaluation of work habits, rather than proving a direct cause-and-effect relationship.
How the Missing Fridays Changed Work Practices
To adapt to fewer working days, teams were encouraged to limit meetings to 30 minutes, keep participants to five or fewer when possible, and increase the use of Microsoft Teams for online communication. The proportion of meetings lasting 30 minutes rose by 46% compared to August 2018, indicating a shift toward shorter, more focused gatherings rather than simply more meetings. Remote meetings also increased by 21% relative to the April-June 2019 period. This forced constraint on available time spurred managers to critically assess whether meetings were necessary and how to optimize them.
Additional Operational and Employee Impacts
With 25.4% fewer working days in August, office resource consumption declined: electricity usage dropped by 23.1%, and paper printing decreased by 58.7%, although these metrics compared August 2019 to August 2016, not 2018, making direct year-to-year comparisons less precise. Employee feedback was overwhelmingly positive, with 92.1% of respondents approving the four-day workweek setup and 94% endorsing the summer project overall. While survey results reflect employee sentiment, they do not guarantee sustained improvements in retention, health, or productivity.
The experiment attracted international media attention, notably through The Guardian, which highlighted the scale of the initiative—2,300 employees receiving five consecutive Fridays off without pay cuts. However, subsequent retellings often overstated the causal impact of the productivity gains linked to the reduced workweek.
Limitations and Broader Perspectives on Reduced Work Time
It is essential to recognize the limitations of this one-month trial. August may have seasonal effects, employees were aware the arrangement was temporary, and Microsoft Japan’s industry and digital infrastructure may not represent sectors like healthcare, manufacturing, retail, or public services, which require continuous operations. Additionally, the experiment combined time off with changes in meeting culture and communication, making it impossible to isolate the impact of any single factor.
Unlike compressed workweeks where employees work the same total hours over fewer days, Microsoft Japan’s model simply eliminated Fridays as working days without extending hours on other days. This distinction matters because evidence from various models of reduced work time cannot be universally applied.
More recent research supports the idea that reducing working hours can improve wellbeing. A 2025 study published in Nature Human Behaviour analyzed six-month, organization-wide four-day-week interventions, finding improvements in multiple wellbeing outcomes. Key to success was the pre-implementation reorganization of work, highlighting that thoughtful redesign—not just removing hours—is crucial. Similar findings emerged from a large UK trial, where employee burnout decreased and many companies chose to continue the shorter workweek.
The Real Takeaway: Work Redesign Over Time Reduction
Microsoft Japan’s experiment challenges the fear that fewer working days necessarily lead to proportional business losses. However, the company explicitly cautioned against interpreting the 39.9% sales increase as a direct causal effect of the shorter week. Instead, the most valuable lesson lies in how the time constraint forced a reimagining of work routines.
The rise in shorter meetings, the increase in remote collaboration, and reduced office resource usage demonstrate how organizations can adapt when time is limited. Most employees favored the arrangement, suggesting benefits beyond mere productivity metrics. Microsoft Japan’s experience shows that while cutting Fridays off the calendar attracted headlines, the deeper insight is in how companies can rethink and eliminate wasted work to maintain or even improve performance.
This experiment remains an instructive example for organizations considering shorter workweeks. The calendar change was not a magic bullet but a catalyst for intentional, strategic work redesign that other companies can learn from and adapt to their unique contexts.
Source: Here
