Month year comparison in javascript

Question

I have two input fields in which we enter Month-year. And display data in graph representation. Field1:Jan-2016 Field2:Jan-2015

I have to compare and this fields and if Field1>Field2 then alert message has to display.

How to do the comparison in java script

Input type format is Month-year

Can you share executable demo/snippet or [JSFiddle](https://jsfiddle.net/) ? — Rayon, Apr 03 '16 at 10:01
Can compare month using `index` of `months array`..And year using `Number comparison` — Rayon, Apr 03 '16 at 10:02
Possible duplicate of [Compare two dates with JavaScript](http://stackoverflow.com/questions/492994/compare-two-dates-with-javascript) — Maen, Apr 03 '16 at 10:03
Could you please share the fiddle with example. I couldn't make itthis format. — , Apr 03 '16 at 10:04

Ali Mamedov · Answer 1 · 2016-04-21T08:56:05.637

You can use this small sample in your code

var date_1 = new Date('2017', '01');
var date_2 = new Date('2015', '02');

if (date_1.getTime() > date_2.getTime()) {

  /* YOUR CODE */
}

Update: 2016/04/21

With + operator (more laconic):

if (+new Date('2017', '01') > +new Date('2015', '02')) {

  /* YOUR CODE */
}

By using valueOf():

if (new Date('2017', '01').valueOf() > new Date('2015', '02').valueOf()) {

  /* YOUR CODE */
}

Nina Scholz · Answer 2 · 2016-04-03T16:21:21.713

You can separate your strings and have a lookup for the month number and return the wanted comparison.

function greater(f1, f2) {
    function getDate(f) {
        var d = f.split('-');
        d[0] = { jan: 1, feb: 2, mar: 3, apr: 4, may: 5, jun: 6, jul: 7, aug: 8, sep: 9, oct: 10, nov: 11, dec: 12 }[d[0].toLowerCase()] || 0;
        return d;
    }

    var d1 = getDate(f1),
        d2 = getDate(f2);
    return d1[1] > d2[1] || d1[1] === d2[1] && d1[0] > d2[0];
}

document.write(greater('Jan-2016', 'Jan-2015') + '<br>');
document.write(greater('Feb-2016', 'Jan-2016') + '<br>');
document.write(greater('Feb-2014', 'Jan-2016') + '<br>');

score 0 · Answer 3 · answered Apr 03 '16 at 10:06

0

You can use a JavaScript Date object to compare your dates:

new Date("Jan-2016") > new Date("Jan-2015") //-> true

answered Apr 03 '16 at 10:06

Bee

88
3

You'll get "Invalid Date" if you do that, Date can't parse that format. – moopet Apr 03 '16 at 10:08

score 0 · Answer 4 · answered Apr 03 '16 at 10:06

Ideally you should compare Date objects, but Date can't parse strings of the format you use.

If you format the date as "2015-01" and "2016-01" you can use Javascript's Date objects to compare them.

This gives you the benefit that you can continue to use these as actual date representations in your script, should you need to.

Note: if you format the date as, ex, "201501" and "201601" you can use simple greater-than or less-than comparisons instead.

So you need to:

Split the date string up into month and year
Convert the month string to an integer
Make a new variable to contain the formatted date
Compare the formatted dates

score 0 · Answer 5 · answered Apr 03 '16 at 10:15

0

You can use a JavaScript library moment.js.

To get the date object, use

var date1= moment("Jan-2016","MMM-YYYY");

Similarly do it for second date and then just compare them as date1 > date2.

answered Apr 03 '16 at 10:15

Sandeep Sukhija

1,156
16
30

score 0 · Answer 6 · answered Oct 12 '20 at 08:52

If you have the consistent string format of "YYYY-MM", e.g. "2020-10", "2021-01", you don't even have to convert them to date for accurate comparison, just compare the string value directly if you just want to know which month is the later month.

Try this:

var d1 = "2020-12";
var d2 = "2021-01";

var greaterMth = d2 > d1 ? d2 : d1;

alert("Greater month is: " + greaterMth);

But for your case, that will be:

var d1 = new Date("Jan-2016");
var d2 = new Date("Jan-2015");

greaterMth = d2 > d1 ? "Jan-2015" : "Jan-2016";
    
alert("Greater month is: " + greaterMth);

You don't even have to bother about the 1st of the month generated by the new Date().

Month year comparison in javascript

6 Answers6