The four-day week moved from fringe idea to mainstream experiment in a few years. Large coordinated pilots ran in the UK, the US, Canada, Ireland, Australia and elsewhere. The headline finding is consistent: most participating companies kept some form of shorter week afterwards. In the UK pilot, 89% of firms were still running a four-day week a year later. In the US and Canadian pilot, none of the 41 companies returned to five days.
Not all four-day weeks are the same
| Model | Hours | Pay | Best for |
|---|---|---|---|
| 100-80-100 | About 80% of previous | Unchanged | Knowledge work where output can be measured |
| Compressed (4×10) | Unchanged | Unchanged | Shift-based teams, operations |
| 9/80 | Unchanged over two weeks | Unchanged | Engineering and public-sector teams wanting a gentler step |
| Pro-rata four days | 80% | 80% | Individuals who want time more than money |
Model your own numbers with the four-day week calculator.
Why it can work
The day off is not where the gains come from. They come from the redesign it forces: fewer and shorter meetings, clearer priorities, protected focus time and less low-value work. Teams that just remove Friday and change nothing else tend to struggle.
Where it’s harder
- Customer-facing coverage: stagger days off so service runs five days.
- Shift and care work: often needs extra hiring, or a compressed model.
- Billable-hour businesses: need pricing changes, such as value-based fees.
A six-step pilot plan
- Define output metrics before you start — what does “100% productivity” mean for each team?
- Audit time for two weeks: meetings, interruptions, tools and duplicate work.
- Redesign work: cut or shorten meetings, set async defaults, agree response times.
- Choose a coverage model: everyone off Friday, or rotating days off.
- Run for three to six months with monthly check-ins.
- Decide with data: keep, adjust or stop.
Proposing it as an employee
Start smaller: ask for a personal compressed-hours or 9/80 trial, or a pro-rata four-day contract. Show results, then propose a team pilot. Use our request letter generator and choose “four-day week.”