# evansiroky/timezone-boundary-builder

A tool to extract data from Open Street Map (OSM) to build the boundaries of the world's timezones.

Repository: https://github.com/evansiroky/timezone-boundary-builder
Canonical: https://ross.abutalabs.com/products/timezone-boundary-builder
Language: JavaScript
License: MIT
License Family: permissive
Topics: timezone, maps, openstreetmap
Last push: 2026-07-11T06:36:04+00:00

## Health v2 (maintenance only)
Score: 89/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 92, release rhythm 80, longevity 100
- inputs: {"age_days": 3729, "days_push": 53, "days_rel": 53, "gap_med": 67.0, "n_releases_24m": 7}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1114, forks 95 (observed 2026-08-28T04:03:38.278567+00:00)

## What it is
A tool and dataset project that builds the world's timezone boundaries from OpenStreetMap data, released as shapefiles and GeoJSON. Each boundary is linked to an IANA timezone identifier like America/Los_Angeles.

## Use cases
- convert lat/lon coordinates to timezone identifiers
- download timezone boundary shapefiles for GIS
- build offline timezone lookup from GPS coordinates
- get timezone polygons as GeoJSON
- map timezones for a scheduling app
- generate timezone boundaries from OpenStreetMap data

## When to choose
- you need to determine a timezone from geographic coordinates offline
- you need accurate timezone polygons for mapping or analysis
- you want data aligned with the IANA timezone database

## When to avoid
- you only need the current UTC offset for a timezone name without geometry
- you need real-time timezone change alerts rather than periodic boundary data

## Facets
- artifact type: dataset
- maturity: active
- function: geospatial, data-generation, etl
- domain: -
- platform: cross-platform, cli
- tags: timezone-boundaries, openstreetmap, shapefile, geojson, iana-timezones, gis, maps, geospatial, data-engineering, nodejs

## Member repositories
- evansiroky/timezone-boundary-builder (main) score 89

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:38.278567+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:42:30.745290+00:00, confidence not recorded.
  - readme: https://github.com/evansiroky/timezone-boundary-builder (fetched 2026-08-28T04:03:38.278567+00:00, sha fb50c0c30b0c)
- Data as of 2026-08-30T08:39:29.467469+00:00.