getWeeksInYear
Signature
Section titled “Signature”getWeeksInYear(value: string): number | nullReturn the number of ISO weeks (52 or 53) in the ISO week-numbering year containing value.
- Uses
value’s ISO week-numbering year (Temporal.PlainDate.yearOfWeek), not its calendar year — late-December/early-January dates can belong to a different ISO week-year than their calendar year (e.g. 2021-01-01 is ISO week-year 2020’s week 53). - Counted as the days from the week-year’s week 1 (the Monday-started week holding January 4) to the next week-year’s week 1, divided by 7. Computed by day arithmetic, so the dates at the range edges count too, although the neighbouring week 1 lies outside the representable range.
- Returns null on invalid input.
Parameters
Section titled “Parameters”| Parameter | Type | Description |
|---|---|---|
value | string | ISO PlainDate string |
Returns
Section titled “Returns”52 or 53, or null on invalid input
Examples
Section titled “Examples”import { getWeeksInYear } from "@northguild/gmt/plain/calculate";
getWeeksInYear("2024-06-15") // 52