how to compare tow date in javascript code example

Example 1: compare dates in js

var date1 = new Date('December 25, 2017 01:30:00');
var date2 = new Date('June 18, 2016 02:30:00');

//best to use .getTime() to compare dates
if(date1.getTime() === date2.getTime()){
    //same date
}

if(date1.getTime() > date2.getTime()){
    //date 1 is newer
}

Example 2: string compare on date in js

var d1 = Date.parse("2012-11-01");
var d2 = Date.parse("2012-11-04");
if (d1 < d2) {
    alert ("Error!");
}