date-from-timezone

Construct date instances within timezone context or resolve date/time information for given timezone

Having timezone and date & time information resolve regular date instance that reflects given time point, or having timezone and date instance resolve date & time information for given timezone.

Light implementation which resolves needed data through natively available (in all modern engines, both browsers and Node.js) Intl.DateTimeFormat.

If loaded in environment which does not provide Intl.DateTimeFormat or of which support is incomplete, module resolves to null

Examples

Construct date instances in specific timezone context

var dateFromTimezone = require("date-from-timezone");

var getWarsawDate = dateFromTimezone("Europe/Warsaw");
var getShanghaiDate = dateFromTimezone("Asia/Shanghai");

// Signature of getXDate follows: Date(yearOrTimeValue[, month[, date[, hour[, minutes[, seconds[, milliseconds]]]]])
var warsawNoon = getWarsawDate(2017, 6, 5, 12);
// also e.g.
warsawNoon = getWarsawDate(Date.parse("7/5/2017 12:00:00 PM"));

var shanghaiNoon = getShanghaiDate(2017, 6, 5, 12);

console.log(warsawNoon.toISOString()); // "2017-07-05T10:00:00.000Z" (12PM in Warsaw was at 10AM UTC)
console.log(shanghaiNoon.toISOString()); // "2017-07-05T04:00:00.000Z" (12PM in Shanghai was at 4AM UTC)

Resolve date & time information for given timezone

var getTokenize = require("date-from-timezone/get-tokenize");

var warsawTokenize = getTokenize("Europe/Warsaw");
var shanghaiTokenize = getTokenize("Asia/Shanghai");

console.log(warsawTokenize(new Date(Date.UTC(2017, 6, 5, 10))));
// { year: 2017, month 6, date: 5, hours: 12, minutes: 0, seconds: 0, milliseconds: 0 }

console.log(shanghaiTokenize(new Date(Date.UTC(2017, 6, 5, 4))));
// { year: 2017, month 6, date: 5, hours: 12, minutes: 0, seconds: 0, milliseconds: 0 }

// We can also retrieve date object. It's important to understand that it won't reflect given time
// point (so should not be used for date timestamp comparisons) but can be used as interim value
// to be used to get formatted date string
console.log(String(shanghaiTokenize(new Date(Date.UTC(2017, 6, 5, 4))).dateObject));
// In CEST Timezone it'll log:
// "Wed Jul 05 2017 12:00:00 GMT+0200 (CEST)"

Installation

$ npm install date-from-timezone

Tests

$ npm test