It wasn’t hard for Samantha Losey, managing director of Unity, a public relations firm in London, to convince her team to work fewer hours for the same paycheck.

But it was an uphill battle to persuade her own board to join the world’s biggest pilot of the four-day work week.

“I had to fight very hard for us to do this as a business… nobody was willing. Everyone was very traditionalist,” Losey told CNN Business.

The main concern centered on whether a 20% cut to weekly working hours would lead to a drop in output, and cause clients to flee.

But after a “very difficult journey” to convince her board, and a rocky start, Losey said her team has hit its stride. She said she is 80% sure everyone will keep the routine after November, when the trial ends.

“[My head] would roll like Marie Antoinette’s if I said to this team ‘we’re not doing this anymore’,” she said.

Unity is one of 70 companies in the United Kingdom participating in the trial. For six months starting in June, more than 3,300 employees have worked 80% of their usual hours — for the same rate of pay — in exchange for promising to deliver 100% of their usual work.

The program is being run by the nonprofit organization 4 Day Week Global; Autonomy, a think tank; and the 4 Day Week UK Campaign, in partnership with researchers from Cambridge University, Oxford University and Boston College.

Already, the trial is bearing fruit for workers hungry for more free time.

Halfway into the pilot, 95% of companies surveyed by 4 Day Week Global say their productivity levels have either stayed the same or improved, while 86% say they are likely to make the routine permanent.

For Gary Conroy, founder and CEO of 5 Squirrels, a skincare product manufacturer on England’s south coast with 13 full-time employees, the new work routine gets “better and better all the time,” he told CNN Business.

Some of the benefits were unexpected.

“We’ve all lost a lot of weight…we were overweight before,” he said. “[The team has] more time to prepare food, [eat] healthily. Lots of people are going to the gym a lot more.”

Good for business?

Four months into the trial, Losey said her clients are happy with their performance, while her team is much more inspired and creative. An internal study at the company found that productivity was up 35% and staff said they were feeling healthier and happier, compared to before the trial.

Now, people are scrambling to join the company.

“We were dying at the beginning of the year trying to find talent and we were spending money on recruiters left, right and center,” she said.

But since Unity joined the program, Losey said she’s “never ever had so many applications,” saving the business a lot of money in recruitment costs.

While her board is still skeptical about the impact on the business output, Unity’s clients are “desperate” for the experiment to pay off, she said — so they can convince their bosses to adopt the routine in their own workplaces.

“[I] literally had a client today saying… I’m going to take it to the HR department,” Losey added.

Juliet Schor, a professor of sociology at Boston College, told CNN Business’ Christine Romans that the four-day work week provides “a major competitive advantage for firms in the labor market.”

It also makes for happier and healthier employees, Schor said. That’s especially important given the demands of the pandemic pushed many to simply burn out.

“Americans are finding that two days is not enough for the weekend. They can’t get all of their errands and family care [done] and taking their kids to activities, and even just a little bit of time for themselves, and preparing for the work week,” she said. “All of that gets crammed into two days and it’s just not enough.”

“The five-day week is just not working for people anymore,” Schor added.

Yet a four-day work week is no silver bullet.

In June, a Gallup survey of more than 12,000 workers in the United States found that while those working a four-day week reported higher well-being — particularly among those required to work on-site — there was no corresponding uptick in levels of engagement in their jobs.

“Having higher engagement comes down to how you’re managed, and just giving someone a four-day work week isn’t necessarily going to mean that you’re well managed and that you’re engaged in your work,” Jim Harter, chief scientist of workplace and well-being at Gallup, told CNN Business.

No Monday blues

For Losey, adjusting to the new routine was painful, however.

She described the first week as “Armageddon,” with too few colleagues available to respond to a client emergency. “I just sat down on the kitchen floor and cried,” she said.

Slowly, the team has adapted, and introduced new habits that have made all the difference. Now, internal meetings are capped to 15 minutes, and client meetings to 30 minutes. Emails to colleagues are not allowed to exceed more than a quarter of a day’s total emails.

In particular, Losey’s staff swears by a “traffic light” system to reduce distractions in the office. Colleagues have a light on their desk, and set it to green if they are happy to talk, amber if they are busy but available to speak, and red if they do not want to be interrupted.

“If [their] button is red, go after someone at your peril,” Losey said.

Conroy said he has introduced “deep work time” where, for two hours every morning and two hours every afternoon, his staff ignore emails, calls or instant messages and concentrate on their projects.

His team has even started unplugging the office phones, as they were too distracting. Clients were initially bothered, he said, but have since responded by sending more emails.

Losey said the risks to the business have been worth seeing through.

“After us having had several smooth weeks… it feels like ‘how would we go back?’ How did we work five days?’ It just seems so un-human,” she said.

“No one has Monday blues here,” she added.