Employees’ experience with the four-day week also remained highly positive, with an unchanged positive rating of nine out of 10 beyond the trial’s conclusion.
Employees' physical and mental health improved slightly, though burnout increased by 0.05%.
Dale Whelehan, CEO of 4 Day Week Global, said the long-term results show a four-day week is sustainable.
He said: “A concern we frequently hear is there’s no way the results from our six-month trials can be maintained, as the novelty eventually must wear off. But here we are, a year later, with benefits only continuing to grow.
“This is very promising for the sustainability of this model and we look forward to tracking companies’ experiences well into the future.”
More on the four-day week:
Four-day week trial hailed a success for businesses and workers
Four-day work week doesn't have to be a headache
Businesses hail "transformative" four-day week pilot
However, not all participants in the trial found that hours have continued to decrease.
Speaking to HR magazine, Claire Daniels, CEO of marketing agency Trio Media, said: “Our workload has intensified somewhat since the trial ended, so I'm finding now that our team is working more hours than they did on the trial.
“This is still less in total than working a normal working week, so the four-day week is still a benefit, but it's not perfect. This could just be a more realistic view of longer-term reduced working hours, or it may just be reflective of our workload at Trio Media at the moment.”
Separate research from recruitment company Hays found more employers have implemented, or are considering implementing, a nine-day fortnight (28%), rather than a four-day week (22%).
A nine-day fortnight is a compressed work pattern where each employee has one extra day off every two weeks, typically every other Friday.
Jen Locklear, chief people officer at ConnectWise, said the four-day week can be complex to implement.
Speaking to HR magazine, she said: “From an employer side, there is complexity in scheduling around a four-day week and ensuring that your customer base continues to get consistent attention and service to which they are accustomed.
“From an employee standpoint, there is flexibility concern because routine tasks like doctor’s appointments might now have the expectation of being scheduled on an employee’s day off.
“If employees have requested a four-day work week, I would encourage employers to dig deeper to determine if that is really what they want, or if they’re simply looking for more flexibility and a break from the routine.”
Locklear said employers struggling to maintain a four-day week could use different types of flexible working.
She added: “Employers could consider identifying the slower months of the year, such as summer holidays, and offer a few months of four-day weeks instead of a perpetual programme that they may then have to backtrack.
“For companies that can absorb it, shutting down an extra day a quarter could help with burnout, morale, and engagement. This could be a more effective and productive alternative than increasing the number of hours an employee is working in a day.”
The Employment Relations (Flexible Working) Bill received royal assent yesterday (20 July) granting employees across England, Scotland and Wales new powers when requesting flexible work arrangements.
Employees can now make up to two flexible working requests within 12 months, and employers will have to respond to the request within two months rather than three.
The bill has also introduced a new requirement to consult with employees before flexible working requests are denied.
Respondents to 4 Day Week Global's survey are from 419 organisations across the US, Canada, the UK and Ireland.
