Place data identifies the city. Time-zone rules translate an instant. Neither supplies proof that this server’s clock is synchronized.
City location data
City location data: GeoNames, used under Creative Commons Attribution 4.0; curated and normalized by Clock.live.
Clock.live selects a smaller search catalog from the source, normalizes names and aliases, and gives same-name places distinguishable routes and region labels. Search coverage is intentionally separate from the smaller set of individually reviewed city pages. Inclusion is not a claim of official municipal endorsement.
Versions used by this build
These are the versions committed for this build, not a claim that every newly announced rule change is already included. Local source files and download checksums are retained with the project for reproducible validation.
| Item | Pinned value |
|---|---|
| Catalog source retrieved | 2026-09-08 |
| Search catalog records | 500 |
| Time-zone package | @js-joda/timezone 2.25.2 |
| IANA rule version in that package | 2026a |
| Supported local conversion/preview years | 1970–2100 |
Time-zone rules can change
The IANA database records time-zone and daylight-saving rules for representative locations. Governments can change those rules, including future transitions. The application uses its pinned rule set consistently rather than mixing browser-specific zone calculations into conversion results.
A city’s named zone is more useful than a permanent numeric offset for future planning. Historical information and future rules still have limits. Check important arrangements against a reliable local authority when a recent rule change may affect them.
The live time source is separate
The browser samples Clock.live’s time endpoint, which reports request receive/send timestamps and the server’s available synchronization-health information. The app estimates network delay and retains an honest fallback when usable synchronization is unavailable.
On a local machine without a valid health record, server synchronization remains unknown. Installing a time-zone package does not synchronize a server clock. The accuracy guide explains source labels and why the page does not claim a certified maximum timing error.
Corrections and attribution
For a suspected location or rule error, include the city/region, named zone, exact date/time and a source supporting the correction. Use the published contact address to report a correction. A local test pass does not verify every place or every historical transition.