Every organisation has a version of the same person: twenty-five years of experience, the one who knows why the system works the way it does, quietly doing the sums on retiring early — not because the work has stopped being interesting, but because five days a week of it has started to cost more than it returns. When they go, the knowledge walks out with them, and the recruitment market rarely sends a replacement with anything like the same depth.
A shorter week is one of the few levers that speaks directly to that calculation. It is time to treat it as what it increasingly is in ageing workforces: a labour-supply strategy, not a perk.
The demographic problem nobody can hire their way out of
Across much of Europe, the working-age population is shrinking. Germany’s four-day-week pilot was explicitly discussed in the context of demographic change — millions leaving the workforce over the coming decade — and employer attractiveness to experienced staff featured in why firms took part. The same arithmetic is arriving, at different speeds, in most developed economies: fewer younger workers entering, more experienced workers reaching the age where they can choose to leave, and hard-to-fill roles concentrated exactly where experience matters most.
In that market, the contest for a 58-year-old specialist is not only about salary. It is about whether working at all remains compatible with health, caring responsibilities — often for parents as well as grandchildren — and a life that no longer fits around the edges of a five-day week. An employer who can offer four days is not offering a discount on labour. They are keeping labour in the market that would otherwise exit it entirely.
Why time works where other retention levers stall
Older workers are rarely the ones a pay rise most influences. By the time someone is weighing early retirement, the marginal value of money is often falling and the marginal value of time is rising sharply. A day a week is a 20 percent increase in non-working life. It is time for medical appointments that currently consume annual leave, for recovery that makes the other four days genuinely productive, and for the gradual, chosen wind-down that abrupt retirement does not allow.
The alternative employers usually offer is part-time work at pro-rata pay — which is precisely the deal many experienced staff refuse, because the workload rarely shrinks in proportion to the hours. A reduced-hours week at full pay, with workload actually redesigned, is a different proposition: it keeps income and status intact while cutting the thing that has become scarce, which is time and energy.
The health side of staying longer
The health evidence supports taking this seriously. The large peer-reviewed research on shorter weeks finds improvements in burnout, mental and physical health, with gains linked to better sleep and less fatigue. For staff in their fifties and sixties, those are not abstract wellbeing metrics. They are the difference between working sustainably for another decade and leaving at the first financially viable moment.
Design it for the people you are trying to keep
If retention after 50 is the goal, design choices matter. A fixed Friday off may suit some; others will value a midweek day that breaks the week into two manageable stretches, or flexibility to align the day with caring commitments. Ask, rather than assuming. And avoid the compressed version of the offer: four ten-hour days can be a worse bargain for older bodies than five shorter ones, and the research on compressed schedules and health is mixed at best. The value is in fewer hours, not in the same hours repackaged.
Be careful, too, with equity. A shorter week offered only to senior staff will be read as an executive perk and resented accordingly. The cleaner approach is a model available across the workforce, communicated partly in retention terms: this is how we keep experience in the building. Younger staff, who will also benefit, generally understand that argument — they work alongside the people it keeps.
Finally, plan the knowledge question deliberately. A four-day week for your most experienced person is also four-fifths as much informal mentoring, corridor diagnosis and “ask her, she’ll know” availability. Pair the change with explicit knowledge transfer: documented decisions, structured mentoring time inside the four days, named deputies. Done well, the shorter week becomes the mechanism that finally forces knowledge out of one head and into the organisation — while its owner is still there to teach it.
Losing experienced staff early is usually recorded as a retirement. Often it is a resignation from a five-day shape of work that no longer fits a longer life. Change the shape, and many of those people stay — to the considerable benefit of everyone who would otherwise have had to replace them.
Sources
- University of Münster, Germany 2024 four-day-week pilot, reported Oct 2024 — https://phys.org/news/2024-10-hours-germany-wide.amp
- HR Brew, Germany pilot continuation results, 24 Oct 2024 — https://www.hr-brew.com/stories/2024/10/24/world-of-hr-73-of-german-companies-that-tried-a-four-day-workweek-will-keep-the-schedule
- Fan, Schor, Kelly & Gu (2025), Nature Human Behaviour four-day-week study, reported Jul 2025 — https://www.psypost.org/large-scale-trial-finds-four-day-workweek-improves-employee-well-being-and-physical-health/
- Autonomy / Alda, Iceland shorter-hours trials 2015–19, reported Jul 2021 — https://phys.org/news/2021-07-shorter-week-boost-productivity-burnout.html
Day5Group is a consultancy that assists in the transition to a 4 day work week. More about Day5Group · All blog articles