Clockjumper Research · Series
Workday Overlap Studies
One shared 223-city, four-gate dataset and one overlap engine — how the world's timezones shape which places can actually meet, hand off, and work together.
ClockJumper studies are produced with AI assistance and human review. · research methodology
When the world can
actually meet
5 studies built from a single dataset: the 9-to-5 workday overlap for every one of 24,753 pairs across 223 cities, computed twice a year so daylight saving is baked in.
Studies in this series
The Remote Work Overlap Report
Across 223 major cities and 24,753 city pairs, the average two cities share about three hours of the 9-to-5 workday — but nearly a third share none of it.
The Most & Least Connected Cities
A ranking of all 223 major cities by average 9-to-5 overlap with the rest of the world, showing where to base a global team — and where geography makes that impossible.
How Daylight Saving Breaks Your Calendar
More than a third of city pairs change their workday overlap between January and July — this study measures who gains, who loses, and who never changes their clocks.
The Meridian Rule
Time-zone overlap is set almost entirely by east–west distance, not total distance — every region has a natural delivery partner on its own meridian.
Does 9-to-5 Matter? A Window Sensitivity Analysis
Recompute every headline figure across six workday windows. Start time is irrelevant; length is everything — and at ten hours San Francisco's isolation reverses.
Shared resources
Methodology
Shared across every study in this series.
Dataset (CC BY 4.0)
ClockJumper Global Workday Overlap Dataset (2026) · CSV download.
Questions & Answers
Every FAQ across the series in one place.
Series canonical: https://clockjumper.com/research/overlap · Site: https://clockjumper.com