timepiece/node_modules/date-fns/getISOWeek.mjs

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2024-05-14 14:54:12 +00:00
import { millisecondsInWeek } from "./constants.mjs";
import { startOfISOWeek } from "./startOfISOWeek.mjs";
import { startOfISOWeekYear } from "./startOfISOWeekYear.mjs";
import { toDate } from "./toDate.mjs";
/**
* @name getISOWeek
* @category ISO Week Helpers
* @summary Get the ISO week of the given date.
*
* @description
* Get the ISO week of the given date.
*
* ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date
*
* @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 date - The given date
*
* @returns The ISO week
*
* @example
* // Which week of the ISO-week numbering year is 2 January 2005?
* const result = getISOWeek(new Date(2005, 0, 2))
* //=> 53
*/
export function getISOWeek(date) {
const _date = toDate(date);
const diff = +startOfISOWeek(_date) - +startOfISOWeekYear(_date);
// Round the number of weeks 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(diff / millisecondsInWeek) + 1;
}
// Fallback for modularized imports:
export default getISOWeek;