Iceland reduced hours for 2,500 workers, and within four years, 86% of the country had followed.
Between 2015 and 2019, the Icelandic government and the Reykjavik City Council ran two large-scale trials of a shorter working week, involving approximately 2,500 employees across offices, hospitals, nurseries, and social services.1 Workers moved from a standard forty-hour week to thirty-five or thirty-six hours, with no reduction in pay. The trial covered more than one percent of Iceland's entire workforce.
Productivity was either maintained or slightly improved across participating workplaces. Workers reported lower stress, reduced burnout, and better work-life balance. Men in heterosexual relationships reported doing more housework.2
Unions used the results as leverage in collective bargaining. By 2022, roughly eighty-six percent of Iceland's working population had either shifted to shorter hours or gained the right to negotiate them.3
In 2022, sixty-one companies and approximately 2,900 workers participated in the United Kingdom's six-month trial, the largest coordinated four-day week pilot to date. Of the sixty-one companies, fifty-six continued with the shorter week after the trial ended. Eighteen made the change permanent.4
The UK trial found a thirty-nine percent reduction in stress, a seventy-one percent reduction in burnout, and a fifty-seven percent drop in resignations. Revenue stayed broadly the same, rising 1.4 percent on average during the trial period.4
Microsoft Japan trialed a four-day week in 2019 and reported a forty percent increase in productivity. Belgium passed legislation in 2022 allowing employees to compress their hours into four days, though without reducing the total. Spain, Portugal, and several other countries have launched national pilot programs. As of 2024, Iceland's GDP growth rate of 4.1 percent exceeded both the European and OECD averages.5