You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
43 lines
1.8 KiB
43 lines
1.8 KiB
import getTimezoneOffsetInMilliseconds from '../_lib/getTimezoneOffsetInMilliseconds/index.js';
|
|
import startOfISOWeek from '../startOfISOWeek/index.js';
|
|
import requiredArgs from '../_lib/requiredArgs/index.js';
|
|
var MILLISECONDS_IN_WEEK = 604800000;
|
|
/**
|
|
* @name differenceInCalendarISOWeeks
|
|
* @category ISO Week Helpers
|
|
* @summary Get the number of calendar ISO weeks between the given dates.
|
|
*
|
|
* @description
|
|
* Get the number of calendar ISO weeks between the given dates.
|
|
*
|
|
* 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} dateLeft - the later date
|
|
* @param {Date|Number} dateRight - the earlier date
|
|
* @returns {Number} the number of calendar ISO weeks
|
|
* @throws {TypeError} 2 arguments required
|
|
*
|
|
* @example
|
|
* // How many calendar ISO weeks are between 6 July 2014 and 21 July 2014?
|
|
* var result = differenceInCalendarISOWeeks(
|
|
* new Date(2014, 6, 21),
|
|
* new Date(2014, 6, 6)
|
|
* )
|
|
* //=> 3
|
|
*/
|
|
|
|
export default function differenceInCalendarISOWeeks(dirtyDateLeft, dirtyDateRight) {
|
|
requiredArgs(2, arguments);
|
|
var startOfISOWeekLeft = startOfISOWeek(dirtyDateLeft);
|
|
var startOfISOWeekRight = startOfISOWeek(dirtyDateRight);
|
|
var timestampLeft = startOfISOWeekLeft.getTime() - getTimezoneOffsetInMilliseconds(startOfISOWeekLeft);
|
|
var timestampRight = startOfISOWeekRight.getTime() - getTimezoneOffsetInMilliseconds(startOfISOWeekRight); // Round the number of days 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((timestampLeft - timestampRight) / MILLISECONDS_IN_WEEK);
|
|
} |