Microsoft Japan tested a four-day workweek and has found the experiment a huge boon to employee productivity.

The tech giant recorded an almost 40% jump in productivity levels after cutting its work hours as part of a wider project to promote healthier work-life balance, CNBC reports.

Microsoft’s “Work Life Choice Challenge,” held this August, saw the firm close its doors on Fridays and give its 2,300 employees three-day weekends for the full month to assess the merits of a reduced workweek.

Over that period, the firm saw productivity, as measured by sales per employee, rise 39.9% compared with August 2018. That boon was thanks in part, Microsoft said, to meetings capped at 30 minutes and an increase in remote conferences. Meanwhile, the firm saw a fall in costs, with 23.1% less electricity used and 58.7% fewer pages printed over the period.

The experiment, which also incorporated self-development and family wellness schemes, recorded largely positive feedback from employees, too, with 92.1% saying they liked the four-day workweek, according to the firm.

Microsoft Japan says its now planning to conduct a similar work-life challenge this winter, aimed at encouraging greater flexible working.