Data and Credits

Where Geoid Globe's maps come from.

Time zones

Time zone boundaries: timezone-boundary-builder by Evan Siroky, built from OpenStreetMap data, made available under the Open Database License (ODbL) 1.0. © OpenStreetMap contributors.

Time zone rules and names: the IANA tz database (public domain).

Earth's shape (geoid)

Geoid heights: EGM2008, National Geospatial-Intelligence Agency (NGA), via the PROJ data grids.

The app's time zone grid (ODbL)

Geoid Globe uses a simplified grid made from the timezone-boundary-builder data. That grid is a derivative database, so it is offered here under the same licence, the ODbL 1.0:

• zone_index.bin: one time zone per point of a 0.5° grid, 361 rows (latitude +90 to −90) × 720 columns (longitude −180 to 179.5), each an unsigned 16-bit little-endian index into zone_names.txt.
• zone_names.txt: one IANA time zone id per line.
• build_data.py: the script that makes them from timezones-with-oceans.geojson (timezone-boundary-builder releases) and the EGM2008 grid.

You may use, share and adapt this grid under the ODbL. If you publish a database made from it, it must also be under the ODbL, and you must credit timezone-boundary-builder and OpenStreetMap contributors.