The four-day work week: what the trials show

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1. 1

   The results are in: the UK's four-day week pilot

   Autonomy (with 4 Day Week Global, Cambridge and Boston College researchers)Published Feb 21, 2023Checked Sep 30, 2026

   “Of the 61 companies that participated, 56 are continuing with the four-day week (92%), with 18 confirming the policy is a permanent change. Revenue rose 1.4% on average; 71% of employees had reduced burnout.”

2. 2

   Going public: Iceland's journey to a shorter working week

   Autonomy and AldaPublished Jul 4, 2021Checked Sep 30, 2026

   “Trials between 2015 and 2019 covered more than 2,500 public-sector workers; productivity and service provision remained the same or improved in the majority of workplaces.”

3. 3

   Work time reduction via a 4-day workweek finds improvements in workers' well-being

   Nature Human Behaviour (Fan et al.)Published Jul 21, 2025Checked Sep 30, 2026

   “Across 141 organisations and 2,896 employees in six countries, four-day week trials were associated with lower burnout and better job satisfaction, mental and physical health compared with 12 control companies.”

4. 4

   Four-day workweek (Wikipedia)

   WikipediaPublished Oct 1, 2026Checked Oct 4, 2026

   “A four-day workweek is an arrangement where a workplace or place of education has its employees or students work or attend school, college or university over the course of four days per week rather than the more customary five-day workweek. This arrangement can be a part of flexible working hours, and is sometimes used to cut costs. The four-day week movement has grown considerably in recent years, with increasing numbers of businesses and organizations around the world trialing and moving permanently to a four-day working week of around 32 hours, with no less pay for workers. Most of these businesses and organizations have involved white collar work, and found that a four-day week is a win-win for employees and employers, as trials have indicated that it leads to a better work-life balance, lower stress-levels, and increased productivity, mainly by eliminating wasted work time.”

5. 5

   Designing the work week in healthcare: a systems agenda for safer, sustainable work.

   BMJ open quality (Whelehan & Ridgway)Published Aug 5, 2026Checked Oct 4, 2026

   “These mechanisms provide a plausible systems-level explanation for how redesigning working time can simultaneously improve human sustainability and organisational effectiveness. Drawing upon complexity science, the paper proposes a mechanism-based theory of change in which temporal redesign stabilises reinforcing fatigue loops and strengthens adaptive capacity within healthcare systems.ConclusionsFatigue should be understood not solely as an occupational health issue but as an indicator of systemic temporal imbalance. Working-time redesign offers a promising governance intervention capable of improving workforce sustainability while maintaining organisational performance. Rather than framing shorter working hours as a workforce benefit alone, healthcare organisations should recognise time as critical infrastructure that can be intentionally designed, governed and evaluated as a core patient safety variable. Future research should determine the optimal temporal architectures for different healthcare contexts and establish time as a measurable dimension of healthcare quality and safety.”

6. 6

   Assessing health, wellbeing, and working life impacts of a 4-day week: a multimodal protocol.

   Frontiers in psychology (Armitage et al.)Published Aug 17, 2026Checked Oct 4, 2026

   “The primary outcome measure is the difference in physical and mental health from baseline to the end of the trial among participants undergoing a reduction in working time, compared with the control group. Data collection is currently underway, and while the majority of employers in the working time reduction group adopt a 4-day week format, the specific change in working patterns is flexible and varies between employers according to their operational need, including a 9-day fortnight, two half-days and shorter working days. Core variables include brain structure and function, sleep, immune function, interoception (perception of bodily sensations), time use, diet, mental health, and workplace performance and engagement. Secondary outcomes include weekly monitoring of self-reported wellbeing changes to identify key inflection points and assess whether these are maintained at a 6-month follow-up. Overall, this study aims to generate highly novel multimodal data on the psychological and biological implications of working time reduction, including observed changes in health, wellbeing, and performance.”