import { getRoundingMethod } from "./_lib/getRoundingMethod.mjs"; import { differenceInDays } from "./differenceInDays.mjs"; /** * The {@link differenceInWeeks} function options. */ /** * @name differenceInWeeks * @category Week Helpers * @summary Get the number of full weeks between the given dates. * * @description * Get the number of full weeks between two dates. Fractional weeks are * truncated towards zero by default. * * One "full week" is the distance between a local time in one day to the same * local time 7 days earlier or later. A full week can sometimes be less than * or more than 7*24 hours if a daylight savings change happens between two dates. * * To ignore DST and only measure exact 7*24-hour periods, use this instead: * `Math.trunc(differenceInHours(dateLeft, dateRight)/(7*24))|0`. * * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc). * * @param dateLeft - The later date * @param dateRight - The earlier date * @param options - An object with options * * @returns The number of full weeks * * @example * // How many full weeks are between 5 July 2014 and 20 July 2014? * const result = differenceInWeeks(new Date(2014, 6, 20), new Date(2014, 6, 5)) * //=> 2 * * @example * // How many full weeks are between * // 1 March 2020 0:00 and 6 June 2020 0:00 ? * // Note: because local time is used, the * // result will always be 8 weeks (54 days), * // even if DST starts and the period has * // only 54*24-1 hours. * const result = differenceInWeeks( * new Date(2020, 5, 1), * new Date(2020, 2, 6) * ) * //=> 8 */ export function differenceInWeeks(dateLeft, dateRight, options) { const diff = differenceInDays(dateLeft, dateRight) / 7; return getRoundingMethod(options?.roundingMethod)(diff); } // Fallback for modularized imports: export default differenceInWeeks;