import { startOfDecade } from "https://deno.land/x/date_fns@v2.5.1/index.js";
Examples
// The start of a decade for 21 October 2015 00:00:00:
var result = startOfDecade(new Date(2015, 9, 21, 00, 00, 00))
//=> Jan 01 2010 00:00:00
// The start of a decade for 21 October 2015 00:00:00: var result = startOfDecade(new Date(2015, 9, 21, 00, 00, 00)) //=> Jan 01 2010 00:00:00