53 lines
1.8 KiB
JavaScript
53 lines
1.8 KiB
JavaScript
|
"use strict";
|
||
|
|
|
||
|
|
Object.defineProperty(exports, "__esModule", {
|
||
|
|
value: true
|
||
|
|
});
|
||
|
|
exports.default = getISOWeeksInYear;
|
||
|
|
|
||
|
|
var _index = _interopRequireDefault(require("../startOfISOWeekYear/index.js"));
|
||
|
|
|
||
|
|
var _index2 = _interopRequireDefault(require("../addWeeks/index.js"));
|
||
|
|
|
||
|
|
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
|
||
|
|
|
||
|
|
var MILLISECONDS_IN_WEEK = 604800000;
|
||
|
|
/**
|
||
|
|
* @name getISOWeeksInYear
|
||
|
|
* @category ISO Week-Numbering Year Helpers
|
||
|
|
* @summary Get the number of weeks in an ISO week-numbering year of the given date.
|
||
|
|
*
|
||
|
|
* @description
|
||
|
|
* Get the number of weeks in an ISO week-numbering year of the given date.
|
||
|
|
*
|
||
|
|
* ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date
|
||
|
|
*
|
||
|
|
* ### v2.0.0 breaking changes:
|
||
|
|
*
|
||
|
|
* - [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes).
|
||
|
|
*
|
||
|
|
* @param {Date|Number} date - the given date
|
||
|
|
* @returns {Number} the number of ISO weeks in a year
|
||
|
|
* @throws {TypeError} 1 argument required
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* // How many weeks are in ISO week-numbering year 2015?
|
||
|
|
* var result = getISOWeeksInYear(new Date(2015, 1, 11))
|
||
|
|
* //=> 53
|
||
|
|
*/
|
||
|
|
|
||
|
|
function getISOWeeksInYear(dirtyDate) {
|
||
|
|
if (arguments.length < 1) {
|
||
|
|
throw new TypeError('1 argument required, but only ' + arguments.length + ' present');
|
||
|
|
}
|
||
|
|
|
||
|
|
var thisYear = (0, _index.default)(dirtyDate);
|
||
|
|
var nextYear = (0, _index.default)((0, _index2.default)(thisYear, 60));
|
||
|
|
var diff = nextYear.valueOf() - thisYear.valueOf(); // Round the number of weeks to the nearest integer
|
||
|
|
// because the number of milliseconds in a week is not constant
|
||
|
|
// (e.g. it's different in the week of the daylight saving time clock shift)
|
||
|
|
|
||
|
|
return Math.round(diff / MILLISECONDS_IN_WEEK);
|
||
|
|
}
|
||
|
|
|
||
|
|
module.exports = exports.default;
|