startOfISOWeekYear
import { startOfISOWeekYear } from "https://esm.sh/v135/date-fns@3.6.0/index.d.mts";@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
function startOfISOWeekYear<DateType extends Date>(date: DateType | number | string): DateType;