go-tz

Time zone lookup by Lon and Lat

Usage

import "github.com/ugjka/go-tz/v2"

Example

// Loading Zone for Line Islands, Kiritimati
zone, err := tz.GetZone(tz.Point{
    Lon: -157.21328, Lat: 1.74294,
})
if err != nil {
    panic(err)
}
fmt.Println(zone[0])

[ugjka@archee example]$ go run main.go
Pacific/Kiritimati

Uses simplified shapefile from timezone-boundary-builder

GeoJson Simplification done with mapshaper

Features

• The timezone shapefile is embedded in the build binary
• Supports overlapping zones
• You can load your custom geojson shapefile if you want
• Sub-millisecond lookup even on old hardware

Problems

• Shapefile is simplified using a lossy method so it may be inaccurate along the borders
• This is purely in-memory. Uses ~50MB of ram

Licenses

The code used to look up the timezone for a location is licensed under the MIT License.

The data in the timezone shapefile is licensed under the Open Data Commons Open Database License (ODbL).