tzwhere

Determine timezone from lat/long in NodeJS

Installation

Installing tzwhere

npm install tzwhere

Example Usage

var tzwhere = require('tzwhere')
tzwhere.init();

var whiteHouse = {'lat': 38.897663, 'lng': -77.036562};

// Determine the timezone of the White House
console.log(tzwhere.tzNameAt(whiteHouse['lat'], whiteHouse['lng']));

// Determine the current offset from UTC, in milliseconds, of the White House's timezone
console.log(tzwhere.tzOffsetAt(whiteHouse['lat'], whiteHouse['lng']));

yields:

America/New_York
-14400000

or

America/New_York
-18000000

depending on the current state of daylight savings time in the America/New_York timezone. You can also do it asynchronously.

...
tzwhere.tzNameAt(whiteHouse['lat'], whiteHouse['lng'], function (error, result) {
	if (error) {
		console.log(error);
	} else {
		console.log(result);
	}
}
...

You can also pass alternative GeoJSON shape files:

var tzwhere = require('tzwhere')
tzwhere.init('path/to/alternative/tz/file');

...

Check the tests for more comprehensive usage, including determining the timezone offsets at arbitrary dates (very useful for scheduling future events expressed in local time).

License

tzwhere is free software, and is distributed under the terms of the MIT license (see LICENSE.txt).