timespace

Compute fuzzy local time from a location. The default accuracy is zoom level 8. See "Regenerate timezones.json" section for instructions on how to change accuracy.

Timezone data is from https://github.com/evansiroky/timezone-boundary-builder/.

Install

npm install @mapbox/timespace

Test

npm run test

Use

Functions

var ts = require('@mapbox/timespace');

var timestamp = Date.now();
var point = [-122.27783203125, 37.84015683604136];
var time = ts.getFuzzyLocalTimeFromPoint(timestamp, point);
//=> (a `moment-timezone` object – see https://momentjs.com/timezone/)


var tile = [41, 98, 8];     // the tile [x, y, z] whose timezone we want to know
var timezone1 = ts.getFuzzyTimezoneFromTile(tile);
//=> 'America/Los_Angeles'


var quadkey = '02301021';   // the quadkey whose timezone we want to know
var timezone2 = ts.getFuzzyTimezoneFromQuadkey(quadkey);
//=> 'America/Los_Angeles'

./lib/timezones.json file contains the timezone name of every z8 tile that contains land.

If a tile/quadkey with zoom levels > 8 is passed into timespace functions, the timezone of its z8 parent is returned.

If a tile/quadkey with zoom levels < 8 is passed into timespace functions, the most popular timezone amongst its z8 children is returned.

Regenerate timezones.json

To update timezone.json,

1. find the link address of the latest timezones.shapefile.zip release from https://github.com/evansiroky/timezone-boundary-builder/releases,
2. replace the link address in this line with the the link from step 1
3. run npm run regenerate
4. run npm run test to verify the new timezones.json file is ok

To generate timezone.json for another zoom level:

1. change the number in this line to the desired zoom level,
2. run npm run regenerate
3. run npm run test to verify the new timezones.json file is ok