JSFiddle - React, Tailwind, and code Playground

JavaScript

var a = new Date();
a.setDate(15);
alert(a);
a = a.getTime();
var b = new Date();
b.setDate(32);
alert(b);
b = b.getTime();
var c = b-a;
var date = new Date(c);
alert(date.getDate()-1);