JSFiddle - React, Tailwind, and code Playground

by akmiecik

HTML

<span id="week_num"></span>

JavaScript

var week = new Date();	
var oneJan = new Date(week.getFullYear(),0,1);
var numberOfDays = Math.floor((week - oneJan) / (24 * 60 * 60 * 1000));
var week_num = Math.ceil((week.getDay() + 1 + numberOfDays) / 7);	
document.getElementById("week_num").innerHTML = week_num;