The world's largest-ever trial of a four-day working week in Iceland has been hailed as an "overwhelming success" and has prompted calls for similar research in the UK.
The trial was organised by Reykjavik city council and took place between 2015 and 2019.
People on nine to five contracts, or shifts with similar amounts of hours, had their working week cut to 35 or 36 hours without a reduction in pay.
The trials featured 2,5000 employees - or around 1% of Iceland's working population - in many settings including schools, hospitals and offices.
The results found productivity and wellbeing improved for all the workers who took part.Following the trial, Icelandic trade unions secured a general reduction in working hours, or the option to reduce working, for 86% of Iceland's working population.
The success of the trial has prompted calls for similar experiments in the UK.
Will Stronge, Director of Research at Autonomy, (a think tank that wrote a report on the Iceland trial) said: "This study shows that the world’s largest ever trial of a shorter working week in the public sector was by all measures an overwhelming success.
"It shows that the public sector is ripe for being a pioneer of shorter working weeks – and lessons can be learned for other governments.
"Iceland has taken a big step towards the four-day working week, providing a great real-life example for local councils and those in the UK public sector considering implementing it here in the UK."
There have been trials into a four-day working week in the UK in the past but the change in working patterns brought on by the pandemic has put a spotlight on drives to improve work-life balance.
Polling has shown both workers and managers are keen to explore more flexible ways of working.
Research commissioned by the 4 Day Week Campaign, showed just over half of workers want to see permanent changes to working life after the pandemic, including a four day week.
A poll of more than 2,000 business leaders by Owl Labs, found just under 40% of them were considering moving their staff to a four-day week and the vast majority said they were keen to "explore progressive policies post-pandemic".
Ahead of the 2019 election, then shadow chancellor John McDonnell announced ambitions for a 32-hour working week to apply to all employees and it would be implemented over a 10-year period.
Sir Keir Starmer's Labour party hasn't committed to maintaining the policy but several front-benchers have said they believe it should still be investigated.
In the UK, different trials have had different results, but the complexity of cutting one working day from the week has proved difficult.
The Wellcome Trust, a medical research charity based in central London, had to abandon its four-day week trial in 2019 after concluding "that it is too operationally complex to implement."The Advice Direct call centre in Scotland successfully made the switch to a four-day week in 2018 on full pay, they said they found productivity and motivation improved because of the change.