About ZoneShift

ZoneShift is a focused reference site for one job: helping distributed teams figure out a meeting time that works for every city involved. It is deliberately small, deliberately fast, and deliberately free of accounts, tracking and pop-ups.

Who built this

ZoneShift is operated by a small team of engineers and operations folks who, between them, have run distributed teams across San Francisco, Berlin, Lagos, Bangalore, Manila and Sydney. We grew tired of every other time-zone tool: some are lovely but won't load on a flaky office Wi-Fi connection; others are encyclopaedic but visually overwhelming; most assume you are a traveller, not a remote-team operator who runs the same dozen comparisons every week.

So we built the version we wanted: stable URLs for every city, a meeting planner that highlights the safe slot rather than making you eyeball a colour-coded grid, and a converter that you can land on directly without ever clicking through a homepage.

Where the data comes from

The list of cities, their populations, countries and IANA identifiers is sourced from publicly available datasets. The current build was generated from the following source:

geonames-cities15000
2026-05-03T01:54:10+00:00
cities=600
timezones=137
countries=109

The seed script first attempts to query the Wikidata SPARQL endpoint at https://query.wikidata.org/ for cities with population above 100,000. If that endpoint is rate-limited or unreachable from the build environment, the script falls back to the GeoNames cities15000 dataset (cities with population above 15,000), filtered to a comparable population threshold.

Time zone offsets, abbreviations and daylight saving information are read from PHP's bundled IANA Time Zone Database (timezonedb), which mirrors the upstream IANA tz data. This is the same database used by virtually every modern operating system, so the values you see on ZoneShift will match what your calendar app and your terminal show.

What ZoneShift is not

ZoneShift does not store a per-user history of comparisons. It does not show ads outside the lightly marked placeholder slots in the layout. It does not require an account. It is, intentionally, just a reference: a stable, fast, server-rendered website that you can bookmark and that will still work in a browser two laptops from now.

If you want a feature we don't have, please tell us — we read every message and we ship things people actually use. We will never email you back asking for a sales call.