startOfHour
import { startOfHour } from "https://esm.sh/v135/date-fns@3.6.0/index.d.mts";
@example
// The start of an hour for 2 September 2014 11:55:00:
const result = startOfHour(new Date(2014, 8, 2, 11, 55))
//=> Tue Sep 02 2014 11:00:00
function startOfHour<DateType extends Date>(date: DateType | number | string): DateType;