Though this experiment took place in New Zealand, the results suggest it could have just as profound an effect in countries with similar economies, including the UK. A shorter workweek isn’t just about sleeping in for an extra day. British employees on average work 42 hours a week, making us the country with the longest working week in Europe. Londoners in particular reportedly work on average three weeks a year more than the rest of the UK . A four-day workweek (with, crucially, five-day pay) could not only help lots of workers make ends meet, but it may also be a more effective way to do so.