Time-zone data

Contains information from Timezone Boundary Builder, made available under the Open Database License (ODbL) 1.0. Boundary data is derived from OpenStreetMap contributors.

Windward Tree uses the unmodified comprehensive boundary dataset packaged with geo-tz 8.1.9. The software is MIT licensed; the boundary database has the separate ODbL license above. Lookups run in Windward Tree's hosting environment; this attribution does not indicate a request to OpenStreetMap or the package authors.

Boundaries are a maintained approximation, not a guarantee of local historical practice. Review the selected time zone near boundaries or for historical matters. Date conversion uses the browser's IANA time-zone rules.