JSFiddle - React, Tailwind, and code Playground

JavaScript

var dateStart = new Date(1990,11,01);
var dateEnd = new Date(1990,11,03);

var dateStart2 = new Date(1990,11,03);
var dateEnd2 = new Date(1990,11,01);

if(Date.parse(dateStart) < Date.parse(dateEnd)){
    alert("DateStart: "+ dateStart + " is less than " + dateEnd);
}else{
    alert("DateEnd: "+ dateEnd+" is less than "+ dateStart);
}    

if(dateStart2 < dateEnd2){
    alert("DateStart: "+ dateStart2 + " is less than " + dateEnd2);
}else{
    alert("DateEnd: "+ dateEnd2+" is less than "+ dateStart2);
}