41 lines
1.4 KiB
JavaScript
41 lines
1.4 KiB
JavaScript
|
"use strict";
|
||
|
|
exports.startOfDecade = startOfDecade;
|
||
|
|
var _index = require("./toDate.cjs");
|
||
|
|
|
||
|
|
/**
|
||
|
|
* The {@link startOfDecade} options.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @name startOfDecade
|
||
|
|
* @category Decade Helpers
|
||
|
|
* @summary Return the start of a decade for the given date.
|
||
|
|
*
|
||
|
|
* @description
|
||
|
|
* Return the start 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).
|
||
|
|
* @typeParam ResultDate - The result `Date` type, it is the type returned from the context function if it is passed, or inferred from the arguments.
|
||
|
|
*
|
||
|
|
* @param date - The original date
|
||
|
|
* @param options - An object with options
|
||
|
|
*
|
||
|
|
* @returns The start of a decade
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* // The start of a decade for 21 October 2015 00:00:00:
|
||
|
|
* const result = startOfDecade(new Date(2015, 9, 21, 00, 00, 00))
|
||
|
|
* //=> Jan 01 2010 00:00:00
|
||
|
|
*/
|
||
|
|
function startOfDecade(date, options) {
|
||
|
|
// 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 = (0, _index.toDate)(date, options?.in);
|
||
|
|
const year = _date.getFullYear();
|
||
|
|
const decade = Math.floor(year / 10) * 10;
|
||
|
|
_date.setFullYear(decade, 0, 1);
|
||
|
|
_date.setHours(0, 0, 0, 0);
|
||
|
|
return _date;
|
||
|
|
}
|