import { getDaysInYear } from "https://deno.land/x/date_fns@v2.5.1/index.js";
Examples
// How many days are in 2012?
var result = getDaysInYear(new Date(2012, 0, 1))
//=> 366
// How many days are in 2012? var result = getDaysInYear(new Date(2012, 0, 1)) //=> 366