2025-12-10 12:02:17 +08:00

37 lines
1.9 KiB
JavaScript

import { toDate } from '../toDate/index.js';
import { tzPattern } from '../_lib/tzPattern/index.js';
import { tzParseTimezone } from '../_lib/tzParseTimezone/index.js';
import { newDateUTC } from '../_lib/newDateUTC/index.js';
/**
* @name fromZonedTime
* @category Time Zone Helpers
* @summary Get the UTC date/time from a date representing local time in a given time zone
*
* @description
* Returns a date instance with the UTC time of the provided date of which the values
* represented the local time in the time zone specified. In other words, if the input
* date represented local time in time zone, the timestamp of the output date will
* give the equivalent UTC of that local time regardless of the current system time zone.
*
* @param date the date with values representing the local time
* @param timeZone the time zone of this local time, can be an offset or IANA time zone
* @param options the object with options. See [Options]{@link https://date-fns.org/docs/Options}
* @param {0|1|2} [options.additionalDigits=2] - passed to `toDate`. See [toDate]{@link https://date-fns.org/docs/toDate}
* @throws {TypeError} 2 arguments required
* @throws {RangeError} `options.additionalDigits` must be 0, 1 or 2
*
* @example
* // In June 10am in Los Angeles is 5pm UTC
* const result = fromZonedTime(new Date(2014, 5, 25, 10, 0, 0), 'America/Los_Angeles')
* //=> 2014-06-25T17:00:00.000Z
*/
export function fromZonedTime(date, timeZone, options) {
if (typeof date === 'string' && !date.match(tzPattern)) {
return toDate(date, { ...options, timeZone });
}
date = toDate(date, options);
const utc = newDateUTC(date.getFullYear(), date.getMonth(), date.getDate(), date.getHours(), date.getMinutes(), date.getSeconds(), date.getMilliseconds()).getTime();
const offsetMilliseconds = tzParseTimezone(timeZone, new Date(utc));
return new Date(utc + offsetMilliseconds);
}