Immunologist Luke O'Neill says that a four-day work week could improve employee mental health and decrease the number of sick days taken.

In a study including 61 companies and 2,900 volunteering employees, 71% liked the change and want their work days permanently reduced.

Volunteers reported less burn out, when "you just lose inspiration, you don't want to go to work, it's a drag, you can't do your job properly, you're fed up, you get depressed".

"Clearly having an extra day off is good for your mental health", Prof O'Neill said on the Show Me The Science podcast.

Reduced hours mean workers can start work after their days off "bright eyed and bushy tailed because you've had that break".

There was also a 65% reduction in the number of sick days taken among participants.

"So overall people were throwing less sickies", he said.

"Certainly that was great for the employer because if you take a sick day, that's a pain for the employer."

Work week history

In the nineteenth century, people worked six or seven days out of the week, averaging around 100 hours.

The term 'weekend' was not widely used until the twentieth century.

Henry Ford, founder of Ford Motor Company, was the first to implement a five-day work week in the United States and, with the help of unions, other companies followed.

Pay stayed the same and more jobs were created as a result of the reduced hours.

The days off at the weekend allowed for sports matches to take place, popularising football culture in Britain.

Dublin City Council

Dublin City councillors unanimously backed a motion for a four-day working week in 2021, while trade unions have also encouraged Irish companies to trial the approach.

"I think there's definitely merit with all of the increased challenges in relation to the heating, energy costs, fuel costs and the commute, etc", Caroline Reidy, human resources expert, said.

"And all the build up of childcare costs if somebody's got an additional day of work.

"In jobs where this might be something that's possible - we've already seen some companies trialling the four-day week - including Dublin City Council.

"So let's maybe open our minds to see could this work in other jobs that might suit a four-day week."

Main image shows Prof Luke O'Neill Newstalk studios in Dublin. Picture by: Rory Walsh/ Newstalk