Thousands of workers across the U.K. have this month started working a four-day week as part of a nationwide trial. Thought to provide significant benefits to well-being, productivity, revenue, as well as the environment, it’s a concept that is taking off in other European nations, such as Belgium.

The trial, which started last week, involves around 3,300 workers at 70 companies who will enjoy a four-day week with no effect on pay.