Here's Proof Employees Can Be More Productive With a Four-Day Workweek by Kaitlin Mulhere Slide this research under your CEO’s office door: Less time on the clock really can boost productivity. Microsoft Japan found after a month-long trial that a four-day workweek increased employee productivity by nearly 40%. The experiment “suggests it might be applicable at scale, and even in one of the world’s most notoriously ‘workaholic’ cultures,” reports Quartz.