Major 4-day workweek study suggests that when we work 5 days we spend one doing basically nothing

While many professionals feel their workweek is packed with meetings, deadlines, and constant demands, groundbreaking research reveals a surprising reality: workers can accomplish the same output in 33 hours that traditionally takes 38 hours to complete.

This finding comes from a comprehensive 2023 study conducted by 4 Day Week Global, a nonprofit advocacy organization. The research represents the largest and most extensive examination of four-day workweek implementations to date, and notably, the first to analyze long-term effects rather than short-term pilot programs.

The study's most striking discovery was that as employees adapted to shorter work weeks, their actual working hours continued to decrease without any decline in productivity or output levels.

Evidence points to significant efficiency gains

Previous four-day workweek studies have primarily focused on immediate, short-term impacts rather than sustained implementation effects.

The most notable example was the United Kingdom's comprehensive trial involving over 60 companies and nearly 3,000 employees. This six-month pilot tested the "100:80:100" model—full pay for 80% of traditional working time in exchange for maintaining 100% productivity levels.

The UK trial yielded impressive results: sick days decreased by 65%, most participating businesses maintained or improved productivity, and employee turnover likelihood dropped by 57%, significantly enhancing retention rates. However, the limited duration prevented researchers from understanding longer-term implications.

The 4 Day Week Global study addressed this gap by tracking workers across the United States, Canada, Britain, and Ireland over 18 months. Initial findings at the six-month mark showed improvements in burnout reduction, general health metrics, and job satisfaction levels.

Participants maintained their full salary while receiving an additional day off each week, but retained identical workload responsibilities. The research confirmed that employees successfully maintained productivity levels while working fewer hours.

More significantly, unlike previous studies, this research documented that workers reduced their average weekly hours by approximately four hours—from 38 to 34 hours—after six months of implementation.

This efficiency improvement occurred as employees eliminated workplace inefficiencies that longer schedules typically accommodate, such as unnecessary meetings, allowing for increased focused work periods. The findings suggest that traditional five-day schedules inadvertently encourage time-wasting behaviors that fill available hours.

Workers who continued the four-day schedule for a full year achieved even greater efficiency, reducing their workweek by an additional hour while reporting enhanced work-life balance and continued improvements in mental and physical health.

The organizational benefits proved equally compelling: participating companies experienced a 15% revenue increase throughout the trial period, with results weighted according to company size.

These positive outcomes explain why no participating organization chose to revert to five-day schedules following the trial, and 89% of workers expressed preference to continue with the four-day arrangement.

Implementation challenges require careful consideration

While the research presents compelling arguments for four-day workweeks, workplace experts caution that practical implementation involves significant logistical complexities that could negatively impact some employees.

Charlotte Morriss, associate director at ESP Solicitors, emphasizes the legal complexities: "Businesses cannot unilaterally modify contractual terms." Organizations must navigate extensive contractual modifications requiring employee consent, addressing issues such as part-time worker arrangements who already maintain reduced schedules, determining which weekday will serve as the additional day off, and recalculating holiday compensation structures.

Additionally, while most participants reported improved wellbeing and work-life balance, a small percentage experienced negative outcomes from the transition.

Pierre Lindmark, founder and CEO of management consultancy Winningtemp, notes that "like any organizational change, this approach benefits some employees while creating challenges for others. The four-day workweek structure may not align with every employee's needs or every business model."

Lindmark particularly warns that "reducing office days could increase anxiety and feelings of isolation for some workers who face identical workload demands within compressed timeframes."

These findings underscore the importance of careful planning and individualized approaches when considering four-day workweek implementations, ensuring that efficiency gains don't inadvertently create new workplace stressors for vulnerable employee populations.