subISOWeekYears
import { subISOWeekYears } from "https://esm.sh/v135/date-fns@3.6.0/index.d.mts";@example
// Subtract 5 ISO week-numbering years from 1 September 2014:
const result = subISOWeekYears(new Date(2014, 8, 1), 5)
//=> Mon Aug 31 2009 00:00:00
function subISOWeekYears<DateType extends Date>(date: DateType | number | string, amount: number): DateType;