One Year of a 4-Day Workweek: What We Learned, and What We Did After

7 minute read

On April 1, 2025, ACE launched a one-year trial of a 4-day, 32-hour workweek. The trial has now concluded, every major success metric was met or exceeded, and our Board of Directors has approved a 32-hour week default as permanent policy. Here’s what we did, what we found, and why we think other organizations might want to consider it too.

Why we tried this

ACE’s guiding principles include seeking evidence, doing the most good we can, and being compassionate. So, when multiple people flagged the same idea within a few months of each other — that a shorter workweek might make us both more effective and more desirable to work for — we took it seriously enough to spend 40+ hours researching it before trialing it.

The evidence we found was consistent and more positive than we expected. The UK’s national pilot, one of the earliest and largest trials of its kind, found a 71% drop in burnout and a 65% reduction in sick days among nearly 3,000 workers, and 92% of participating companies chose to continue the policy after the trial ended. Across the broader body of research compiled by 4 Day Week Global, the pattern holds: shorter weeks, at full pay, tend to produce steady or improved output alongside sharply better staff wellbeing.

We also had a practical motivation. ACE’s 2024 compensation review found that our leadership salaries sat 16–24% below movement baselines, and our budget didn’t allow for the raises that would close that gap. A 32-hour week at full pay is, in effect, a raise: research from 4 Day Week Global found that a majority of employees would choose a 4-day week over a comparable pay increase. “When asked how much additional pay they’d require in their next job to go back to five days, 32.8% of employees said 26–50% more, 12.2% would require more than 50%, and over one in ten (13.8%) said no amount of money would induce them to go back to five days.” For an organization competing for talent against better-funded employers, that’s a powerful, yet affordable retention tool.

How we ran the pilot

To prepare for the trial, we spent nearly nine months in consultation with Dr. Alex Soojung-Kim Pang, who helped us prepare staff, set expectations, and build a curriculum for the transition. Before launch, every team audited its meetings and business-as-usual work to cut anything that wasn’t mission-critical, and we invested in AI tools and automation to reclaim staff time. Every team ran a pre-mortem to identify likely failure points in advance.

We set four ground rules for the trial:

• Accountability — staff work together to achieve in 32 hours what we’d previously achieved in 40.
• Seamless for stakeholders — the advocates we support and our partners and funders should not notice any difference in the quality or quantity of our work.
• Flexibility — when mission-critical work required more than 32 hours in a given week, staff worked extra hours to ensure deliverables were met.
• Transparency — we committed to being open about what wasn’t working, and to keep adjusting.

All staff participated, and we closed entirely on Fridays so no one had to worry about bottlenecking colleagues or feeling like they should check in. We kept the same KPIs and set OKRs of comparable scope and ambition to prior years.

What we found

Every one of our three success criteria — increased efficiency, increased wellbeing, and positive retention — was met.

Metric	Result
Key Results achieved	19 of 21
KPIs met	10 of 11
Asana tasks completed vs. prior year	+18.4%
Overdue task rate	~2% (well below our 5% threshold)
Recommended Charity Fund raised	+15% vs. budget, +11.5% vs. prior year
Movement Grants raised	+66% vs. budget, +78.6% vs. prior year
Staff experience score	8.08 / 10 (target: 7.5)
Staff vote to continue	All but one staff member in favor
Staff departures linked to the trial	Zero

Our quarterly wellbeing surveys, which compared staff against their own pre-trial baselines, told an equally clear story:

Wellbeing metric	Change
Burnout	–11.1%
Frequency of high work stress	–12.9%
Work stress overall	–6.8%
Serious consideration of quitting	–6.7%
Work efficiency	+12.3%
Work-life balance	+11.8%
Wage satisfaction	+8.9%
Work ability	+6.6%
Job satisfaction	+5.6%
Sufficient time to complete work	+3.8%

We’re confident these metrics provide the most accurate and comprehensive picture available, though we note a few limitations in attributing changes directly to the trial.

Staff were actively supported in finding efficiencies — including leveraging AI — so we can’t fully isolate how much these gains reflect the shortened week versus improved AI usage. But the trial did motivate us to prioritize AI fluency more quickly than we otherwise would have.

OKRs also shifted significantly between years, limiting direct comparison. Asana task completion, while useful, reflects individual habits that may have changed independently. And while the trial was our primary wellbeing initiative, other factors — permanent uncapped sick leave, improved staff relationships, personal life changes — may have contributed to wellbeing gains.

These caveats are worth noting, but taken together our metrics have convinced us that this new way of working, with minor adjustments, might allow us to do more good.

The ripple effect

Many of our team members noted that they used their extra time to pursue personal projects that brought them joy and made them a more well-rounded person, allowing them to bring renewed energy to their work at ACE.

And while we placed no expectation on staff to use their extra time to help animals, a number of them chose to anyway, extending the net good the ACE team contributed to the animal advocacy movement:

• One staff member wrote and published a book on AI and animal advocacy, co-ran a request for proposals for the AI and Animals project, and joined as a grant reviewer for the Survival and Flourishing Fund.
• Two staff members volunteered with UK Voters for Animals, helping grow it from a few part-time volunteers into a grant-funded operation with a paid coordinator and a mass lobby day in Parliament.
• One staff member took on the board presidency of a Canadian wild animal charity and reviewed a forthcoming book on UK animal policy.
• Others expanded their involvement in co-organizing AVA Academy Asia, volunteering tech support for small nonprofits, creating animal-inspired art, and serving on the Animal Grantmakers board.

What’s changing going forward

We built in the following flexibility to adjust the policy based on what we learned:

• More scheduling flexibility. Instead of requiring everyone to take Fridays off, teams and individuals can now structure their 32 hours differently — sticking to the 4-day week, spreading hours evenly across five days, or with a partial Friday. Fridays remain free of internal meetings for everyone, regardless of schedule.
• Defined “peak periods.” Some work genuinely can’t be compressed into 32 hours year-round, like the giving season for our Development team, or the height of our grant review periods for our Programs team. Directors can now designate peak periods per year (capped at 8 weeks total) where their team temporarily returns to 40 hours. Averaged across the year, this works out to roughly a 33-hour week.
• No more time-off-in-lieu for 33–40 hour weeks. This removes an administrative burden and reduces out-of-office time that was cutting into our ability to find enough overlapping work hours.
• Friday/Saturday public holidays are observed on Friday, rather than the nearest workday, so we have fewer short weeks stacking on top of each other.

Why we’re telling you this

Transparency is one of ACE’s guiding principles, and we think this is the kind of decision stakeholders and peers should be able to see the reasoning behind. This trial cost us almost nothing in direct expense; part-timers’ hourly rates increased, but payroll was minimally impacted. It also functioned as a retention benefit comparable to a substantial raise, at a moment when our budget genuinely couldn’t offer one, and unwanted turnover is costly.

Our results were consistent with the broader research base and with similar trials run elsewhere. The largest controlled study of the 4-day week to date, published in Nature Human Behaviour in July 2025, tracked 2,896 employees across 141 companies in six countries over six months. The study found meaningful drops in burnout, alongside improvements in job satisfaction, work ability, and physical and mental health — with no loss of productivity.

With the right preparation and support, it’s possible to do as much (or more) mission-critical work in less time, with your team being measurably better off. The specific model that worked for ACE won’t be the right fit for every organization’s structure or coverage needs. But we’d encourage any organization in this movement weighing the same tradeoffs to take these experiments seriously. We believe it’s possible to build a more effective, more sustainable movement, and we’re glad to talk with any organization considering a similar trial.

If you have questions about our experience or trial logistics, we’re happy to answer them via people.ops@animalcharityevaluators.org. And if you’re an ACE donor or partner curious about how the trial affected the programs you support, we’d love to hear from you at development@animalcharityevaluators.org.

---

---

---