Compare Two Dates With JavaScript

Compare two dates with JavaScript

The Date object will do what you want - construct one for each date, then compare them using the >, <, <= or >=.

The ==, !=, ===, and !== operators require you to use date.getTime() as in

var d1 = new Date();
var d2 = new Date(d1);
var same = d1.getTime() === d2.getTime();
var notSame = d1.getTime() !== d2.getTime();

to be clear just checking for equality directly with the date objects won't work

var d1 = new Date();
var d2 = new Date(d1);

console.log(d1 == d2);   // prints false (wrong!) 
console.log(d1 === d2);  // prints false (wrong!)
console.log(d1 != d2);   // prints true  (wrong!)
console.log(d1 !== d2);  // prints true  (wrong!)
console.log(d1.getTime() === d2.getTime()); // prints true (correct)

I suggest you use drop-downs or some similar constrained form of date entry rather than text boxes, though, lest you find yourself in input validation hell.

For the curious, date.getTime() documentation:

Returns the numeric value of the specified date as the number of milliseconds since January 1, 1970, 00:00:00 UTC. (Negative values are returned for prior times.)

how to compare two string dates in javascript?

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

Demo Jsfiddle

Recently found out from a comment you can directly compare strings like below

if ("2012-11-01" < "2012-11-04") {
    alert ("Error!");
}

How to compare two dates from input?

This is how I would do it

HTML

<script>
    function compareDates() {
        //Get the text in the elements
        var from = document.getElementById('from').textContent;
        var to = document.getElementById('to').textContent;

        //Generate an array where the first element is the year, second is month and third is day
        var splitFrom = from.split('/');
        var splitTo = to.split('/');

        //Create a date object from the arrays
        var fromDate = Date.parse(splitFrom[0], splitFrom[1] - 1, splitFrom[2]);
        var toDate = Date.parse(splitTo[0], splitTo[1] - 1, splitTo[2]);

        //Return the result of the comparison
        return fromDate < toDate;
    }
</script>

<input id="from" type="date" placeholder="dd/mm/yy"><br>
<input id="to" type="date" placeholder="dd/mm/yy">
<button onclick="compareDates()">Compare</button>

Let me know how you get on.

Comparing date part only without comparing time in JavaScript

I'm still learning JavaScript, and the only way that I've found which works for me to compare two dates without the time is to use the setHours method of the Date object and set the hours, minutes, seconds and milliseconds to zero. Then compare the two dates.

For example,

date1 = new Date()
date2 = new Date(2011,8,20)

date2 will be set with hours, minutes, seconds and milliseconds to zero, but date1 will have them set to the time that date1 was created. To get rid of the hours, minutes, seconds and milliseconds on date1 do the following:

date1.setHours(0,0,0,0)

Now you can compare the two dates as DATES only without worrying about time elements.

Compare two dates in Javascript from an HTML form

Try it:

// You were wrong comparing only the year with the full datevar todaysYear = new Date().getFullYear();
var borndate = document.getElementById("borndate");var form = document.querySelector("form");// Working with forms we want to catch submit (not click) eventsform.addEventListener('submit', comparedate)
function comparedate(evt) {  // preventing default behavior (form submit in this case)  evt.preventDefault();
  // here we translate 'string' value back to 'date' & extract year  var yearOfBirth = new Date(borndate.value).getFullYear()  // an alternative would be to simply parse the year off the string itself
  if (yearOfBirth >= todaysYear) {    alert("Looks like you are to young!");  } else {    // submitting form programmatically    form.submit()  }}

<div class="form">  <form class="login-form" method="POST" action="main.php">    <input type="date" id="borndate" name="borndate" required="required" />    <input type="submit" class="button" name="button" value="submit" />  </form></div>

$(function(){  var d1 = new Date("2001-12-01");  var d2 = new Date("2001-12-01");    console.log(d1.getTime() == d2.getTime());});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

var date1 = moment(new Date(2019, 4, 17).valueOf()).format('MM/DD');
var date2 = moment(new Date(2019, 4, 17).valueOf()).format('MM/DD');

if  (date1 === date2) 
    console.log('true'); 
else 
     console.log('false');

var obj = { 
   startDate1: "02/01/2020", 
   endDate1: "03/01/2020", 
   startDate2:"02/05/2020", 
   endDate2:"02/15/2020"
};
// Create a clone of obj object and convert values to timestamp.
var $dates = {};
$dates.startDate1 = new Date(obj.startDate1).getTime();
$dates.startDate2 = new Date(obj.startDate2).getTime();
$dates.endDate1 = new Date(obj.endDate1).getTime();
$dates.endDate2 = new Date(obj.endDate2).getTime();

if (($dates.endDate1 >= $dates.startDate2 && $dates.startDate1 <= $dates.endDate2) ||
    ($dates.endDate2 >= $dates.startDate1 && $dates.startDate2 <= $dates.endDate1)) {  
         // etc...
}