getDay
import { getDay } from "https://esm.sh/v135/date-fns@3.6.0/index.d.mts";@example
// Which day of the week is 29 February 2012?
const result = getDay(new Date(2012, 1, 29))
//=> 3
function getDay<DateType extends Date>(date: DateType | number | string): number;