The results from the largest multi-country four-day work week trial are in. 141 companies. Approximately 2,900 employees. Six countries: Australia, Canada, New Zealand, the UK, Ireland, and the US. When the trial ended, 92% of participating companies made the policy permanent.
92%
of companies made the four-day week permanent after the trial
Source: 4 Day Week Global / Boston College research programme, published 2025
141
companies across six countries participated in the coordinated trial
Source: 4 Day Week Global, multi-country trial results, 2025
130%
revenue increase at one participating software company during the trial period
Source: 4 Day Week Global, company-level outcomes, 2025
The Data That Ends the Debate
Previous four-day week studies were promising but limited. Small sample sizes, single countries, self-selecting participants. The criticisms were fair: nice idea, insufficient evidence.
This trial addressed every objection. Multiple countries. Multiple industries (tech, manufacturing, professional services, healthcare, non-profit). Independent research oversight from Boston College. Standardised measurement across all participants.
The headline findings:
Four-Day Week Trial Key Metrics
Source: 4 Day Week Global / Boston College research programme, 2025
- Revenue held steady or increased across the majority of participating organisations
- Employee burnout decreased significantly
- Sleep quality improved
- Physical health markers improved
- Absenteeism dropped
- Voluntary turnover decreased
One software company saw revenue increase 130% during the trial period. That's an outlier, but the median outcome was still positive. Organisations didn't just maintain performance on fewer hours. Many improved.
Why It Works
The instinct is to assume that cutting a day means cutting output. The reality, supported by decades of research on knowledge work, is that most organisations operate well below peak efficiency five days a week.
Meetings expand to fill available time. Focus work gets fragmented across long days. Energy and attention decline predictably after sustained periods. A compressed schedule forces deliberate choices about what actually matters.
Companies in the trial reported:
- Fewer and shorter meetings. When time is scarce, meeting culture changes fast.
- More focused deep work. Four days creates urgency that five days dissipates.
- Better energy management. Three-day weekends provide genuine recovery, not the half-rest of a two-day weekend where Sunday is already coloured by Monday anxiety.
The NZ Angle
New Zealand has specific reasons to pay attention. Our economy runs on talent retention in a small labour market. A four-day week is a competitive advantage for organisations that can implement it, particularly in sectors competing with Australian salaries.
Several NZ companies participated in the global trial. The early indicators from domestic participants align with the broader data: maintained output, happier teams, improved retention.
For NZ enterprises considering this model, the question has shifted. It's no longer "does this work?" The evidence is conclusive. It's "can we design our operations to support it?"
The Implementation Reality
Not every organisation can flip a switch. Customer-facing roles, shift-based work, and industries with regulatory requirements need careful design. The trial participants that struggled most were the ones that tried to compress five days into four without changing how work was structured.
The ones that succeeded redesigned workflows first. They asked: what work actually needs to happen? What's habit? What's theatre? That audit, done honestly, typically reveals 15-25% of weekly activity that can be eliminated or restructured without any impact on outcomes.
The productivity argument for the five-day week was always weaker than people assumed - we just never had enough data to challenge it properly. 141 companies across six countries tried it, and 92% said: we're keeping this.
Tim Hatherley-Greene
Chief Operating Officer
The four-day week forces the same discipline we advocate for in AI adoption: audit your processes, cut the waste, invest in the tools that multiply human capability. Organisations that do both will compound the benefits.
Isaac Rolfe
Managing Director
Where to Start
Run a two-week time audit. Track how every hour is spent across a representative team. Categorise: deep work, meetings, admin, coordination, low-value repetition. Most organisations find 20%+ of the week is reclaimable. That's your design space for a compressed schedule.