The 4-hour workday experiment: 18 months of data from 200 knowledge workers.
We didn't expect output to hold. We expected attrition to fall. The opposite happened — and the reason rewires how I think about deep work, calendars, and what we're actually paying people for.
In early 2024 we ran an 18-month experiment across three teams — 200 knowledge workers total — testing a hard 4-hour workday. Same salary, same deliverables, same OKRs. The only constraint: no scheduled work after 1pm local time, and a 90-minute hard cap on meetings per day. Here's what actually happened, including the parts we didn't want to publish.
The surprise: attrition went up, not down
Every public 4-day-week and shorter-week pilot reports falling attrition. Ours rose by 8 percentage points over 18 months. When we dug in, the reason was uncomfortable but clear: the people who left were the ones whose actual contribution didn't fit in 4 hours, and the constraint made that obvious — to them and to their manager. The shorter day didn't burn them out. It exposed mis-fits the 8-hour day had been hiding.
- Low-output ICs who looked busy in meetings.
- Managers whose only contribution was status-gathering.
- Projects that were really 3 weeks of work stretched over 6 months.
- Headcount the org didn't actually need.
- Output became the only legible signal of contribution.
- Status-gathering managers had to find a new value proposition or leave.
- Projects compressed naturally — or got killed.
- Two roles per team turned out to be unnecessary, and were not refilled.
What I'd do differently next time
- Communicate up front that the shorter day is a constraint, not a perk. People who can't deliver inside it will be surfaced. Don't pretend otherwise.
- Give managers 90 days to redesign their role around outcomes, not presence. Most can. Some can't.
- Measure output weekly, not quarterly. The whole experiment hinges on output being legible.
- Don't expect attrition to fall. Expect it to be reshaped — your highest-output people will stay; your meeting-rich, output-light people won't.
HR & Operations leader scaling global remote teams across Nepal, the Philippines, Australia, and the US. Tech-leaning writing lives on Medium.