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
38
|
import { addWeeks } from "./addWeeks.mjs";
import { millisecondsInWeek } from "./constants.mjs";
import { startOfISOWeekYear } from "./startOfISOWeekYear.mjs";
/**
* @name getISOWeeksInYear
* @category ISO Week-Numbering Year Helpers
* @summary Get the number of weeks in an ISO week-numbering year of the given date.
*
* @description
* Get the number of weeks in an ISO week-numbering year 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 number of ISO weeks in a year
*
* @example
* // How many weeks are in ISO week-numbering year 2015?
* const result = getISOWeeksInYear(new Date(2015, 1, 11))
* //=> 53
*/
export function getISOWeeksInYear(date) {
const thisYear = startOfISOWeekYear(date);
const nextYear = startOfISOWeekYear(addWeeks(thisYear, 60));
const diff = +nextYear - +thisYear;
// 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);
}
// Fallback for modularized imports:
export default getISOWeeksInYear;
|
