Incrementing a date in JavaScript

Incrementing a date in JavaScript

I need to increment a date value by one day in JavaScript.
For example, I have a date value 2010-09-11 and I need to store the date of the next day in a JavaScript variable.
How can I increment a date by a day?

Solutions/Answers:

Solution 1:

Three options for you:

1. Using just JavaScript’s Date object (no libraries):

My previous answer for #1 was wrong (it added 24 hours, failing to account for transitions to and from daylight saving time; Clever Human pointed out that it would fail with November 7, 2010 in the Eastern timezone). Instead, Jigar’s answer is the correct way to do this without a library:

var tomorrow = new Date();
tomorrow.setDate(tomorrow.getDate() + 1);

This works even for the last day of a month (or year), because the JavaScript date object is smart about rollover:

var lastDayOf2015 = new Date(2015, 11, 31);
snippet.log("Last day of 2015: " + lastDayOf2015.toISOString());
var nextDay = new Date(+lastDayOf2015);
var dateValue = nextDay.getDate() + 1;
snippet.log("Setting the 'date' part to " + dateValue);
nextDay.setDate(dateValue);
snippet.log("Resulting date: " + nextDay.toISOString());
<!-- Script provides the `snippet` object, see http://meta.stackexchange.com/a/242144/134069 -->
<script src="//tjcrowder.github.io/simple-snippets-console/snippet.js"></script>

(This answer is currently accepted, so I can’t delete it. Before it was accepted I suggested to the OP they accept Jigar’s, but perhaps they accepted this one for items #2 or #3 on the list.)

2. Using MomentJS:

var today = moment();
var tomorrow = moment(today).add(1, 'days');

(Beware that add modifies the instance you call it on, rather than returning a new instance, so today.add(1, 'days') would modify today. That’s why we start with a cloning op on var tomorrow = ....)

3. Using DateJS, but it hasn’t been updated in a long time:

var today = new Date(); // Or Date.today()
var tomorrow = today.add(1).day();

Solution 2:

var myDate = new Date();

//add a day to the date
myDate.setDate(myDate.getDate() + 1);

Solution 3:

None of the examples in this answer seem to work with Daylight Saving Time adjustment days. On those days, the number of hours in a day are not 24 (they are 23 or 25, depending on if you are “springing forward” or “falling back”.)

The below AddDays javascript function accounts for daylight saving time:

function addDays(date, amount) {
  var tzOff = date.getTimezoneOffset() * 60 * 1000,
      t = date.getTime(),
      d = new Date(),
      tzOff2;

  t += (1000 * 60 * 60 * 24) * amount;
  d.setTime(t);

  tzOff2 = d.getTimezoneOffset() * 60 * 1000;
  if (tzOff != tzOff2) {
    var diff = tzOff2 - tzOff;
    t += diff;
    d.setTime(t);
  }

  return d;
}

Here are the tests I used to test the function:

    var d = new Date(2010,10,7);
    var d2 = AddDays(d, 1);
    document.write(d.toString() + "<br />" + d2.toString());

    d = new Date(2010,10,8);
    d2 = AddDays(d, -1)
    document.write("<hr /><br />" +  d.toString() + "<br />" + d2.toString());

    d = new Date('Sun Mar 27 2011 01:59:00 GMT+0100 (CET)');
    d2 = AddDays(d, 1)
    document.write("<hr /><br />" +  d.toString() + "<br />" + d2.toString());

    d = new Date('Sun Mar 28 2011 01:59:00 GMT+0100 (CET)');
    d2 = AddDays(d, -1)
    document.write("<hr /><br />" +  d.toString() + "<br />" + d2.toString());

Solution 4:

The easiest way is to convert to milliseconds and add 1000*60*60*24 milliseconds e.g.:

var tomorrow = new Date(today.getTime()+1000*60*60*24);

Solution 5:

Tomorrow in one line in pure JS but it’s ugly !

new Date(new Date().setDate(new Date().getDate() + 1))

Here is the result :

Thu Oct 12 2017 08:53:30 GMT+0200 (Romance Summer Time)

Solution 6:

You first need to parse your string before following the other people’s suggestion:

var dateString = "2010-09-11";
var myDate = new Date(dateString);

//add a day to the date
myDate.setDate(myDate.getDate() + 1);

If you want it back in the same format again you will have to do that “manually”:

var y = myDate.getFullYear(),
    m = myDate.getMonth() + 1, // january is month 0 in javascript
    d = myDate.getDate();
var pad = function(val) { var str = val.toString(); return (str.length < 2) ? "0" + str : str};
dateString = [y, pad(m), pad(d)].join("-");

But I suggest getting Date.js as mentioned in other replies, that will help you alot.