What the trials actually show about health and happiness
The most direct evidence comes from a 2025 study of 218 employees at a Lithuanian heating company who had already switched to a four-day week. The results were overwhelmingly positive: 97% rated the change positively, 42% said their general health improved, 85% were satisfied with their work-life balance, 70% reported better emotional well-being, and 28% said their stress dropped [1]. These are large, self-reported gains, and they align with broader reviews: a systematic literature review from 2025 found that four-day week experiments consistently boost happiness and well-being without hurting productivity [4]. A separate legal-policy analysis of UK and Iceland trials also concluded that productivity can be maintained or improved [2].
But these numbers come from a single cross-sectional survey—meaning it measured one group at one point in time, not a controlled experiment. So while the benefits are striking, they may partly reflect the enthusiasm of early adopters or the specific culture of that company. The evidence is promising but not yet definitive.
Where the privacy and fairness risks hide
The same papers that celebrate the four-day week also flag risks that often get less attention. A 2026 legal analysis from Indonesia warns that compressed workweeks (40 hours squeezed into 4 days) can blur the line between work and rest, especially for hybrid or remote workers, leading to 'working-time spillover, hidden overtime, and blurred boundaries between work and rest' [2]. This is a direct fairness and privacy risk: if your workday is longer, you may feel pressure to answer emails or finish tasks outside official hours, eroding personal time. The paper calls for safeguards like transparent time-tracking, wage protection, and a 'right to disconnect'—none of which are standard in most trials [2].
A 2025 study on technological change reinforces this: it found that 35% of remote workers already report musculoskeletal injuries and psychological stress, partly because technology makes it harder to 'switch off' [3]. The same paper notes that an imbalance between technological intensity and workers' sense of control is a key driver of health risks [3]. In other words, a four-day week could amplify these problems if it simply compresses the same workload into fewer, longer days without addressing the underlying pressure to be always-on.
The systematic review adds that flexible schedules like the four-day week need 'clear demarcations' to prevent over-commitment [4]. Without those boundaries, the fairness risk is that some employees—especially those in roles with less control over their time—end up working more, not less, while the privacy risk is that their off-hours are no longer truly off.
Not everyone benefits equally—and that's a fairness problem
The Lithuanian study found that the benefits of the four-day week were not evenly distributed. Employees' age and work tenure made a statistically significant difference: older workers and those with longer tenure reported greater improvements in workability and health [1]. This suggests that younger or newer employees might not see the same gains—or could even face added pressure to prove themselves in a compressed schedule. The study didn't measure fairness directly, but the pattern hints that the four-day week could widen existing inequalities if not carefully designed.
The legal analysis from Indonesia makes this explicit: different models (compressed 40-hour weeks vs. reduced 32–36 hour weeks) carry 'distinct legal implications and risks, particularly in sectors and urban contexts where working-time control is difficult' [2]. For example, a compressed schedule might be feasible for office workers but unfair for gig workers, shift workers, or those in jobs where hours are less flexible. The paper argues that without a legal framework—including overtime limits, transparent recording, and occupational safety protections—the four-day week could create new fairness gaps rather than closing old ones [2].
About These Sources
This answer is built on 5 peer-reviewed studies — published from 2025 to 2026, 5 from 2024 or later, 1 in Q1 journals — selected as the most relevant from 5 studies that passed quality screening, drawn from 52 papers retrieved from a database of over 500 million.
Sources used in this answer
The perceived effects of the four-day work week on employee health, well-being, and workability
In a cross-sectional survey of 218 employees at a Lithuanian heating company, 97% rated the four-day week positively, 42% reported improved general health, 85% were satisfied with work-life balance, and 70% reported better emotional well-being; however, benefits varied significantly by age and tenure, suggesting uneven impacts.
Four-Day Workweek in Indonesia’s Big Cities: Urgency and Legal Framework for Flexible Work in Labour Law Reform
A legal analysis for Indonesia warns that compressed four-day workweeks (40 hours/4 days) risk working-time spillover, hidden overtime, and blurred work-rest boundaries, especially for hybrid/remote workers, and calls for safeguards like wage protection, transparent time-recording, and a right-to-disconnect framework.
The Impact of Technological Change on the Workplace Environment and Employee Health and Countermeasures
A 2025 review of technological change in the workplace reports that 35% of remote workers experience musculoskeletal injuries and psychological stress, and identifies an imbalance between technological intensity and workers' sense of control as a key driver of health risks.
Embracing Flexibility: Exploring the Impact and Future of Remote Work, Flextime, and the Four-Day Workweek on Productivity and Well-Being
A systematic literature review on flexible work arrangements finds that four-day week experiments show potential for increasing happiness and well-being without compromising productivity, but stresses that clear demarcations are needed to prevent over-commitment.
Productivity and the four-day work week
A legal-policy article argues that adopting a four-day workweek in Australian labour law could boost productivity, but does not directly address privacy or fairness risks.