endOfDecade
import { endOfDecade } from "https://esm.sh/v135/date-fns@3.6.0/index.d.mts";@example
// The end of a decade for 12 May 1984 00:00:00:
const result = endOfDecade(new Date(1984, 4, 12, 00, 00, 00))
//=> Dec 31 1989 23:59:59.999
function endOfDecade<DateType extends Date>(date: DateType | number | string): DateType;