36 lines
1.2 KiB
JavaScript
36 lines
1.2 KiB
JavaScript
import { toDate } from "./toDate.mjs";
|
|
|
|
/**
|
|
* @name lastDayOfDecade
|
|
* @category Decade Helpers
|
|
* @summary Return the last day of a decade for the given date.
|
|
*
|
|
* @description
|
|
* Return the last day of a decade for the given 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 original date
|
|
*
|
|
* @returns The last day of a decade
|
|
*
|
|
* @example
|
|
* // The last day of a decade for 21 December 2012 21:12:00:
|
|
* const result = lastDayOfDecade(new Date(2012, 11, 21, 21, 12, 00))
|
|
* //=> Wed Dec 31 2019 00:00:00
|
|
*/
|
|
export function lastDayOfDecade(date) {
|
|
// TODO: Switch to more technical definition in of decades that start with 1
|
|
// end with 0. I.e. 2001-2010 instead of current 2000-2009. It's a breaking
|
|
// change, so it can only be done in 4.0.
|
|
const _date = toDate(date);
|
|
const year = _date.getFullYear();
|
|
const decade = 9 + Math.floor(year / 10) * 10;
|
|
_date.setFullYear(decade + 1, 0, 0);
|
|
_date.setHours(0, 0, 0, 0);
|
|
return _date;
|
|
}
|
|
|
|
// Fallback for modularized imports:
|
|
export default lastDayOfDecade;
|