The idea that we should all work five days a week is so deeply established that most people never think to question it. Yet the five-day week is not a law of nature; it is a relatively recent invention, and one that a growing number of companies and even governments are now beginning to challenge. Around the world, trials of a four-day working week – with no reduction in pay – have produced results striking enough to start a serious debate.

The arguments in favour are compelling. Supporters claim that a shorter week leads to happier, healthier and less stressed employees, who in turn are more productive during the hours they do work. Several trials have reported that output remained the same, or even increased, despite the reduction in hours. Workers, meanwhile, gained an extra day each week for family, rest, hobbies or study. Companies reported that staff were less likely to fall ill or to leave, saving the considerable costs of recruitment.

Naturally, there are objections. Critics argue that a four-day week is simply not practical in every industry. A factory production line, a hospital ward or a busy restaurant cannot easily reduce its hours without hiring more staff, which raises costs. There are concerns, too, that squeezing the same amount of work into fewer days could increase pressure rather than reduce it, leaving employees just as exhausted as before, only over a shorter period.

What most experts agree on is that there is no one-size-fits-all answer. A four-day week may transform life in an office-based company while proving impossible in a factory or a care home. Nevertheless, the very fact that the idea is being seriously discussed represents a significant shift. For most of the last century, the assumption was that we should work as much as possible. The current debate reflects a growing belief that the ultimate purpose of the economy is not simply to maximise work, but to improve the quality of human life – and that how we spend our time may matter just as much as how much we earn.