When does a four-day week improve outcomes, and for whom?
The strongest evidence from a large-scale global trial shows that a four-day workweek with no pay cut consistently improves well-being. In a study of 2,896 employees across 141 organizations, workers reported less burnout, higher job satisfaction, better mental health, and better physical health after a six-month trial [5]. The improvements were linked to three specific factors: better self-reported work ability, fewer sleep problems, and lower fatigue levels [5]. This suggests that when the policy is implemented with genuine workload reduction, it delivers clear benefits.
A separate study of 218 employees at a Lithuanian heating company found that 97% rated the four-day week positively, with 42% reporting improved general health and 85% satisfied with their work-life balance [1]. Notably, 63% said their workability increased, and 27% took fewer sick days [1]. These results align with the global trial, reinforcing that the policy can boost both health and productivity.
However, the benefits are not automatic. A study of 604 employees in Indian service and manufacturing companies found that simply adopting a four-day week did not guarantee performance gains; success depended on factors like strategic planning, viewing the company as a brand, and inspiring happiness at work [4]. In other words, the policy works best when it is part of a broader organizational effort to redesign work, not just a schedule change.
Can a four-day week increase inequality?
Yes, especially for women and workers with fewer resources. A study of female employees at a childcare nonprofit in Portugal found that the four-day week created a paradox: while it promised more free time, women's extra day off was quickly absorbed by childcare, housework, and other gendered obligations [3]. The researchers call this 'temporal recolonization' — the new time is recolonized by unpaid work, rather than providing genuine rest or autonomy [3].
Crucially, the study found that women with higher education and income could navigate these pressures more easily, while those with fewer resources faced intensified coordination burdens [3]. This means the policy can widen existing inequalities if it is not accompanied by changes in workplace culture, social support, and expectations around domestic labor.
The global trial [5] and the Lithuanian study [1] did not report on inequality effects, likely because they focused on average outcomes rather than subgroup differences. This gap is important: a policy that looks successful on average may still leave some groups worse off.
How can organizations implement a four-day week without increasing inequality?
The evidence points to two key ingredients: workload reorganization and equal access to the time off. In the global trial, organizations underwent pre-trial work reorganization to improve efficiency and collaboration, and the well-being gains were tied to actual reductions in hours worked, not just a compressed schedule [5]. This suggests that simply cramming five days of work into four is unlikely to help and may increase stress.
A study of fertility nurses in the UK combined a four-day week with a digital platform that automated administrative tasks, cutting administrative workload by 40% (from 6.5 to 3.9 hours per day) [2]. Nurses reported better work-life balance and more time for direct patient care, and patients felt more informed and in control [2]. This shows that pairing schedule changes with efficiency improvements can benefit both workers and service quality.
To avoid the inequality trap identified in the childcare study [3], organizations need to actively ensure that the extra day off is genuinely free from work and domestic obligations. This might include policies like paid leave for caregiving, flexible scheduling, and cultural shifts that normalize using the day for rest, not just catching up on chores.
About These Sources
This answer is built on 5 peer-reviewed studies — published from 2022 to 2026, 3 from 2024 or later, 2 in Q1 journals — selected as the most relevant from 5 studies that passed quality screening, drawn from 47 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 study 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 27% took fewer sick days [1].
P-516 Technology-driven fertility nursing: how digitalisation and a four-day workweek enhance efficiency, job satisfaction, and patient care in assisted reproductive technology
In a prospective mixed-methods study of five fertility nurses in a UK clinic, combining a four-day week with a digital platform reduced administrative workload by 40% and improved job satisfaction and patient experience [2].
Between temporal liberation and temporal recolonisation: Experiences of time under a four-day workweek
In a qualitative study of female employees at a childcare nonprofit, the four-day week led to 'temporal recolonization' where free time was absorbed by gendered obligations, widening inequalities, especially for women with fewer resources [3].
The Subtle Art of Effecting a Four-day Workweek to Drive Performance
In a survey of 604 employees in Indian service and manufacturing companies, the four-day week improved performance only when combined with strategic planning, brand connection, and happiness at work [4].
Does work time reduction improve workers' well-being? Evidence from global four-day workweek trials
In a global trial of 2,896 employees across 141 organizations, a six-month four-day week trial (with no pay cut) reduced burnout and improved job satisfaction, mental health, and physical health, mediated by better work ability, less fatigue, and fewer sleep problems [5].