node-latlong

Get timezone ID (such as America/Los_Angeles) from coordinates (latitude, longitude).

node-latlong internally uses latlong-cli which is a executable of bradfitz/latlong.

blazingly fast

No external API call. You can even run its method synchronously. It takes just few milliseconds.

lightweight

TL;DR: It's about 2.4MB after install.

There are pre-built binary distributions of latlong-cli for some major platforms in the package but useless executables will be automatically deleted by postinstall npm script when you install node-latlong.

usage

as a Node.js module

$ npm install node-latlong

const getTimezoneByCoords = require('node-latlong');

// use Promise, async / await
try {
    const timezone = await getTimezoneByCoords(37.7833, -122.4167);
    // 'America/Los_Angeles'
} catch (err) {
    // handle error
}

// use callback
getTimezoneByCoords(37.7833, -122.4167, (err, result) => {
    if (err) {
        // handle error
    }
    console.log(result);
    // 'America/Los_Angeles'
});

const getTimezoneByCoordsSync = require('node-latlong/sync');
const timezone = getTimezoneByCoordsSync(37.485419, 126.894239);
// 'Asia/Seoul'

global cli-executable

$ npm install -g node-latlong
$ latlong-cli 37.485419 126.894239
> Asia/Seoul

Keep that in mind the result can be empty string when you run binary directly.

methods

getTimezoneByCoords(latitude: number, longitude: number, [callback: function]): Promise

If callback is provided, Promise always will be resolved without rejection.

getTimezoneByCoordsSync(latitude: number, longitude: number): string

It's synchronous version of getTimezoneByCoords. You can get this method by require('node-latlong/sync').

known issues / things to know

It throws error when the result is empty

The result of bradfitz/latlong can be empty string if the input is junk. In this case, node-latlong throws an error. You can check it by error.emptyResult (boolean).

getTimezoneByCoords(37.7833, -122.4167).catch(err => {
    if (err && err.emptyResult) {
        // throw error or pass it over with kindly tolerance
    }
})

Why I get Asia/Phnom_Penh with this coordinates?

This is an issue of bradfitz/latlong.

I got an error on install

node-latlong doesn't support this platform or processor architecture

-> Please make issue or pull request to add the pre-built binary distribution for your platform/architecture.