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import startOfWeek from '../startOfWeek/index.ts'import getTimezoneOffsetInMilliseconds from '../_lib/getTimezoneOffsetInMilliseconds/index.js'import requiredArgs from '../_lib/requiredArgs/index.ts'import { LocaleOptions, WeekStartOptions } from '../types.ts'
const MILLISECONDS_IN_WEEK = 604800000
/** * @name differenceInCalendarWeeks * @category Week Helpers * @summary Get the number of calendar weeks between the given dates. * * @description * Get the number of calendar weeks between the given dates. * * ### 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 * @param {Object} [options] - an object with options. * @param {Locale} [options.locale=defaultLocale] - the locale object. See [Locale]{@link https://date-fns.org/docs/Locale} * @param {0|1|2|3|4|5|6} [options.weekStartsOn=0] - the index of the first day of the week (0 - Sunday) * @returns {Number} the number of calendar weeks * @throws {TypeError} 2 arguments required * @throws {RangeError} `options.weekStartsOn` must be between 0 and 6 * * @example * // How many calendar weeks are between 5 July 2014 and 20 July 2014? * const result = differenceInCalendarWeeks( *   new Date(2014, 6, 20), *   new Date(2014, 6, 5) * ) * //=> 3 * * @example * // If the week starts on Monday, * // how many calendar weeks are between 5 July 2014 and 20 July 2014? * const result = differenceInCalendarWeeks( *   new Date(2014, 6, 20), *   new Date(2014, 6, 5), *   { weekStartsOn: 1 } * ) * //=> 2 */export default function differenceInCalendarWeeks(  dirtyDateLeft: Date | number,  dirtyDateRight: Date | number,  dirtyOptions?: LocaleOptions & WeekStartOptions): number {  requiredArgs(2, arguments)
  const startOfWeekLeft = startOfWeek(dirtyDateLeft, dirtyOptions)  const startOfWeekRight = startOfWeek(dirtyDateRight, dirtyOptions)
  const timestampLeft =    startOfWeekLeft.getTime() - getTimezoneOffsetInMilliseconds(startOfWeekLeft)  const timestampRight =    startOfWeekRight.getTime() -    getTimezoneOffsetInMilliseconds(startOfWeekRight)
  // 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)}