57 lines
2.4 KiB
JavaScript
57 lines
2.4 KiB
JavaScript
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import startOfWeek from '../startOfWeek/index.js';
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import getTimezoneOffsetInMilliseconds from '../_lib/getTimezoneOffsetInMilliseconds/index.js';
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var MILLISECONDS_IN_WEEK = 604800000;
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/**
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* @name differenceInCalendarWeeks
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* @category Week Helpers
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* @summary Get the number of calendar weeks between the given dates.
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*
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* @description
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* Get the number of calendar weeks between the given dates.
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*
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* ### v2.0.0 breaking changes:
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*
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* - [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes).
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*
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* @param {Date|Number} dateLeft - the later date
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* @param {Date|Number} dateRight - the earlier date
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* @param {Object} [options] - an object with options.
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* @param {Locale} [options.locale=defaultLocale] - the locale object. See [Locale]{@link https://date-fns.org/docs/Locale}
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* @param {0|1|2|3|4|5|6} [options.weekStartsOn=0] - the index of the first day of the week (0 - Sunday)
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* @returns {Number} the number of calendar weeks
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* @throws {TypeError} 2 arguments required
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* @throws {RangeError} `options.weekStartsOn` must be between 0 and 6
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*
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* @example
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* // How many calendar weeks are between 5 July 2014 and 20 July 2014?
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* var result = differenceInCalendarWeeks(
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* new Date(2014, 6, 20),
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* new Date(2014, 6, 5)
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* )
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* //=> 3
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*
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* @example
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* // If the week starts on Monday,
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* // how many calendar weeks are between 5 July 2014 and 20 July 2014?
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* var result = differenceInCalendarWeeks(
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* new Date(2014, 6, 20),
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* new Date(2014, 6, 5),
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* { weekStartsOn: 1 }
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* )
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* //=> 2
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*/
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export default function differenceInCalendarWeeks(dirtyDateLeft, dirtyDateRight, dirtyOptions) {
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if (arguments.length < 2) {
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throw new TypeError('2 arguments required, but only ' + arguments.length + ' present');
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}
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var startOfWeekLeft = startOfWeek(dirtyDateLeft, dirtyOptions);
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var startOfWeekRight = startOfWeek(dirtyDateRight, dirtyOptions);
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var timestampLeft = startOfWeekLeft.getTime() - getTimezoneOffsetInMilliseconds(startOfWeekLeft);
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var timestampRight = startOfWeekRight.getTime() - getTimezoneOffsetInMilliseconds(startOfWeekRight); // Round the number of days to the nearest integer
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// because the number of milliseconds in a week is not constant
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// (e.g. it's different in the week of the daylight saving time clock shift)
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return Math.round((timestampLeft - timestampRight) / MILLISECONDS_IN_WEEK);
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}
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