month should not be greater than 11 and less than 0 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: compare dates in javascript

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
}