39 lines
1.4 KiB
JavaScript
39 lines
1.4 KiB
JavaScript
|
"use strict";
|
||
|
|
exports.lastDayOfISOWeekYear = lastDayOfISOWeekYear;
|
||
|
|
var _index = require("./getISOWeekYear.js");
|
||
|
|
var _index2 = require("./startOfISOWeek.js");
|
||
|
|
var _index3 = require("./constructFrom.js");
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @name lastDayOfISOWeekYear
|
||
|
|
* @category ISO Week-Numbering Year Helpers
|
||
|
|
* @summary Return the last day of an ISO week-numbering year for the given date.
|
||
|
|
*
|
||
|
|
* @description
|
||
|
|
* Return the last day of an ISO week-numbering year,
|
||
|
|
* which always starts 3 days before the year's first Thursday.
|
||
|
|
* The result will be in the local timezone.
|
||
|
|
*
|
||
|
|
* ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date
|
||
|
|
*
|
||
|
|
* @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
|
||
|
|
*
|
||
|
|
* @param date - The original date
|
||
|
|
*
|
||
|
|
* @returns The end of an ISO week-numbering year
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* // The last day of an ISO week-numbering year for 2 July 2005:
|
||
|
|
* const result = lastDayOfISOWeekYear(new Date(2005, 6, 2))
|
||
|
|
* //=> Sun Jan 01 2006 00:00:00
|
||
|
|
*/
|
||
|
|
function lastDayOfISOWeekYear(date) {
|
||
|
|
const year = (0, _index.getISOWeekYear)(date);
|
||
|
|
const fourthOfJanuary = (0, _index3.constructFrom)(date, 0);
|
||
|
|
fourthOfJanuary.setFullYear(year + 1, 0, 4);
|
||
|
|
fourthOfJanuary.setHours(0, 0, 0, 0);
|
||
|
|
const _date = (0, _index2.startOfISOWeek)(fourthOfJanuary);
|
||
|
|
_date.setDate(_date.getDate() - 1);
|
||
|
|
return _date;
|
||
|
|
}
|