hugoWebsite/node_modules/date-fns/getISOWeeksInYear/index.js

48 lines
1.6 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"));
var _index3 = _interopRequireDefault(require("../_lib/requiredArgs/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
*
* @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?
* const result = getISOWeeksInYear(new Date(2015, 1, 11))
* //=> 53
*/
function getISOWeeksInYear(dirtyDate) {
(0, _index3.default)(1, arguments);
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;