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import getTimezoneOffsetInMilliseconds from '../_lib/getTimezoneOffsetInMilliseconds/index.js'import startOfISOWeek from '../startOfISOWeek/index.ts'import requiredArgs from '../_lib/requiredArgs/index.ts'
const 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? * const result = differenceInCalendarISOWeeks( *   new Date(2014, 6, 21), *   new Date(2014, 6, 6) * ) * //=> 3 */export default function differenceInCalendarISOWeeks(  dirtyDateLeft: Date | number,  dirtyDateRight: Date | number): number {  requiredArgs(2, arguments)
  const startOfISOWeekLeft = startOfISOWeek(dirtyDateLeft)  const startOfISOWeekRight = startOfISOWeek(dirtyDateRight)
  const timestampLeft =    startOfISOWeekLeft.getTime() -    getTimezoneOffsetInMilliseconds(startOfISOWeekLeft)  const 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)}