Time Zone boundaries: timezone-boundary-builder 2026f
Source: https://github.com/evansiroky/timezone-boundary-builder/releases/tag/2026f
Original asset: timezones-with-oceans.geojson.zip
Copyright OpenStreetMap contributors and timezone-boundary-builder contributors.
Database licence: Open Data Commons Open Database License (ODbL) v1.0
https://opendatacommons.org/licenses/odbl/1-0/
https://www.openstreetmap.org/copyright

This is a cartographically simplified derivative (Douglas-Peucker, 0.04 degrees;
coordinates rounded to 4 decimal places). All zone features and polygon rings
are retained, including small islands. These are approximate civil time-zone
boundaries, not legal or cadastral boundaries. Current offsets and daylight
saving time are calculated separately from IANA time zone identifiers.

The complete derivative database is freely downloadable alongside this file:
/data/timezones-2026f.json