If we had to pick one pilot to hand a sceptical chief executive, it might be Portugal’s. Not because its wellbeing numbers were the largest — they were solid rather than spectacular — but because it answered the question every leader actually asks: what separates the firms that keep a shorter week from the firms that quietly drift back?
The answer was not enthusiasm. It was process change.
The pilot in brief
Portugal’s government-backed pilot, evaluated by researchers including Pedro Gomes and Rita Fontinha with Birkbeck and Henley Business School, involved 41 companies and roughly 1,000 employees. Companies could choose how to reduce time; a substantial minority chose a nine-day fortnight rather than a four-day week. That design choice matters, because Portugal tested shorter time, not one rigid calendar.
Within months, the share of employees reporting anxiety fell by 21 percent, fatigue by 23 percent, and insomnia or sleep problems by 19 percent. Employers rated the trial about 7.7 out of 10 at four months. Those are self-reported figures from a volunteer pilot, and we should read them as such. They are consistent with the UK, US and Ireland, Iceland and, later, Germany results — direction repeated across very different labour markets.
Then came the more interesting finding.
Two process changes
Continuation was strongly linked to making two or more changes to how work was done. Firms that changed their processes — meetings, workflows, handovers, tools, the everyday mechanics of getting work finished — were far more likely to keep the shorter week. Firms that changed little or nothing were the ones that drifted back.
Read that again, because it overturns the popular version of this idea. The day off did not cause success. The redesign did. The day off was the deadline that forced the redesign.
This finding also explains a frustration we hear from leaders whose pilots disappointed. They gave people a Friday and kept every meeting, approval chain, status report, and inbox habit that consumed the previous five days. Staff then did the only arithmetic available: the same work in fewer hours. Some coped by working faster. Some worked secretly. Some concluded the model was a fraud. Portugal says the problem was upstream of the calendar.
What “process change” looked like in practice
The German pilot a year later, reported in October 2024, gives a helpful picture of the same behaviour in another cohort: 60 percent of firms cut meeting frequency or length, and a quarter adopted new digital tools during the trial. Portugal’s firms were doing the same family of things — fewer and shorter meetings, clearer priorities, better handovers, and deliberate removal of low-value work.
None of this is glamorous. A stop-doing list will never trend on social media. But it is where the hours live. A one-hour weekly meeting with ten people costs ten hours. Three recurring reports that nobody reads can fund a meaningful part of a shorter week for a small team.
Portugal also recorded a predictable cost: coordination. With less overlapping time, some firms found it harder to reach colleagues and keep work moving. That is not an argument against shorter time. It is an argument for core collaboration hours, decision logs, and buddy cover — designed in advance, not improvised after clients start chasing.
The lesson we apply with clients
When we assess readiness, we now ask a Portuguese question: can this organisation name, before it starts, at least two process changes per team — and owners for them? If the answer is no, we do not recommend a start date yet. We recommend a preparation phase.
That is not delay for its own sake. A pilot launched without redesign does not test a four-day week. It tests whether staff can absorb a twenty percent capacity cut. They usually can, briefly, at personal cost. The pilot then records either exhaustion or hidden overtime, and the organisation concludes the model failed. Portugal shows where it actually failed: in the weeks before the first day off was taken.
The encouraging side of the finding is that survival was not reserved for perfect companies. It was associated with ordinary, learnable changes. Two of them. That is a threshold most teams can meet — if leadership gives them permission to stop, shrink, or automate work that no longer earns its time.
Sources
- Gomes & Fontinha, Portugal pilot, via Personnel Today, 14 December 2023 — https://www.personneltoday.com/hr/portugals-four-day-week-reduces-anxiety-and-fatigue/
- University of Münster / Intraprenör / 4 Day Week Global, Germany pilot, reported October 2024 — https://phys.org/news/2024-10-hours-germany-wide.amp
- Autonomy / University of Cambridge / Boston College, UK pilot, reported 21 February 2023 — https://www.sciencedaily.com/releases/2023/02/230221113132.htm
Day5Group is a consultancy that assists in the transition to a 4 day work week. More about Day5Group · All blog articles