Find the next month of a given date in javascript

Question

I have a piece of code to find the next month of the given date.

var d = new Date('2018-03-31');
dt = new Date(d.setMonth(d.getMonth() + 1));
document.getElementById("demo").innerHTML = dt;

But i'm wondering what is wrong here since it adds one month to March & gives May instead of April?

DEMO:

var d = new Date('2018-03-31');

dt = new Date(d.setMonth(d.getMonth() + 1));
document.getElementById("demo").innerHTML = dt;

<p id="demo"></p>

Yes but `31st April` doesn't exists, so it goes to `1st May` — Thum Choon Tat, Mar 27 '18 at 07:19
It adds a month to the date, not just to the month. So you ends up with April 31 that actually becomes may 1 — Lelio Faieta, Mar 27 '18 at 07:20

score 5 · Accepted Answer · answered Mar 27 '18 at 07:25

Use

setMonth(month, day)

d.setMonth(d.getMonth() + 1, 1); where day as 1st day of next month

Only if you are interested in Month part

var d = new Date('2018-03-31');

d.setMonth(d.getMonth() + 1, 1);

dt = new Date(d);
document.getElementById("demo").innerHTML = dt;

<p id="demo"></p>

score 2 · Answer 2 · answered Mar 27 '18 at 07:21

2

There's no 31st April so it goes to 1st May. You can try it with 2018-03-30

var d = new Date('2018-03-30');

dt = new Date(d.setMonth(d.getMonth() + 1));
document.getElementById("demo").innerHTML = dt;

<p id="demo"></p>

answered Mar 27 '18 at 07:21

Thum Choon Tat

`d = new Date("2018-01-30")`... - And what if TO cannot change the string? – Andreas Mar 27 '18 at 07:23
Then how to get `April`? – mpsbhat Mar 27 '18 at 07:24
2

@mpsbhat Check the duplicate – Andreas Mar 27 '18 at 07:25
And also check yogen's answer – Thum Choon Tat Mar 27 '18 at 07:32
Thank you @ThumChoonTat..!!! Understood the error..!! – mpsbhat Mar 27 '18 at 09:28

score 0 · Answer 3 · answered Mar 27 '18 at 07:19

0

setMonth mutates the original Date object - try just setMonth and then referencing the date object again, rather than creating a new one:

var d = new Date('2018-03-31');
d.setMonth(d.getMonth() + 1);
document.getElementById("demo").innerHTML = d;

<p id="demo"></p>

answered Mar 27 '18 at 07:19

That's still May... – Andreas Mar 27 '18 at 07:20
Er, shows Apr for me. Guess it's a timezone issue – CertainPerformance Mar 27 '18 at 07:20

score -1 · Answer 4 · answered Mar 27 '18 at 07:21

-1

April only has 30 days. If you add 1 to month on the 31st of March, you'll be 1 month later, which is the 1st of May.

answered Mar 27 '18 at 07:21

AdrianL

4 Answers4