bc518174
 王天杨
提交两个项目文件
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
|
import { getISOWeekYear } from "./getISOWeekYear.mjs";
import { startOfISOWeek } from "./startOfISOWeek.mjs";
import { constructFrom } from "./constructFrom.mjs";
/**
* @name startOfISOWeekYear
* @category ISO Week-Numbering Year Helpers
* @summary Return the start of an ISO week-numbering year for the given date.
*
* @description
* Return the start of an ISO week-numbering year,
* which always starts 3 days before the year's first Thursday.
* The result will be in the local timezone.
*
* 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 original date
*
* @returns The start of an ISO week-numbering year
*
* @example
* // The start of an ISO week-numbering year for 2 July 2005:
* const result = startOfISOWeekYear(new Date(2005, 6, 2))
* //=> Mon Jan 03 2005 00:00:00
*/
export function startOfISOWeekYear(date) {
const year = getISOWeekYear(date);
const fourthOfJanuary = constructFrom(date, 0);
fourthOfJanuary.setFullYear(year, 0, 4);
fourthOfJanuary.setHours(0, 0, 0, 0);
return startOfISOWeek(fourthOfJanuary);
}
// Fallback for modularized imports:
export default startOfISOWeekYear;
|
