Calculating Days in JS: A Beginner's Guide

Ever wanted to know what numerical "day of the year" a date falls on (e.g., January 31st is day 31, but February 1st is day 32)?

We can do this easily by subtracting January 1st from our target date and converting milliseconds into days!

JavaScript

function dayOfTheYear(date) {

const year = date.getFullYear();