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?

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();

var myDate = new Date();

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

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());

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);

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)

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.


Getting the next 5 days:

var date = new Date(),
d = date.getDate(),
m = date.getMonth(),
y = date.getFullYear();


for(i=0; i < 5; i++){
var curdate = new Date(y, m, d+i)
console.log(curdate)
}

Two methods:

1:

var a = new Date()
// no_of_days is an integer value
var b = new Date(a.setTime(a.getTime() + no_of_days * 86400000)

2: Similar to the previous method

var a = new Date()
// no_of_days is an integer value
var b = new Date(a.setDate(a.getDate() + no_of_days)

Get the string value of the date using the dateObj.toJSON() method Ref: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toJSON Slice the date from the returned value and then increment by the number of days you want.

var currentdate = new Date();
currentdate.setDate(currentdate.getDate() + 1);
var tomorrow = currentdate.toJSON().slice(0,10);

 Date.prototype.AddDays = function (days) {
    days = parseInt(days, 10);
    return new Date(this.valueOf() + 1000 * 60 * 60 * 24 * days);
}

Example

var dt = new Date();
console.log(dt.AddDays(-30));
console.log(dt.AddDays(-10));
console.log(dt.AddDays(-1));
console.log(dt.AddDays(0));
console.log(dt.AddDays(1));
console.log(dt.AddDays(10));
console.log(dt.AddDays(30));

Result

2017-09-03T15:01:37.213Z
2017-09-23T15:01:37.213Z
2017-10-02T15:01:37.213Z
2017-10-03T15:01:37.213Z
2017-10-04T15:01:37.213Z
2017-10-13T15:01:37.213Z
2017-11-02T15:01:37.213Z

Not entirelly sure if it is a BUG(Tested Firefox 32.0.3 and Chrome 38.0.2125.101), but the following code will fail on Brazil (-3 GMT):

Date.prototype.shiftDays = function(days){    
  days = parseInt(days, 10);
  this.setDate(this.getDate() + days);
  return this;
}

$date = new Date(2014, 9, 16,0,1,1);
$date.shiftDays(1);
console.log($date+"");
$date.shiftDays(1);
console.log($date+"");
$date.shiftDays(1);
console.log($date+"");
$date.shiftDays(1);
console.log($date+"");

Result:

Fri Oct 17 2014 00:01:01 GMT-0300
Sat Oct 18 2014 00:01:01 GMT-0300
Sat Oct 18 2014 23:01:01 GMT-0300
Sun Oct 19 2014 23:01:01 GMT-0200

Adding one Hour to the date, will make it work perfectly (but does not solve the problem).

$date = new Date(2014, 9, 16,0,1,1);

Result:

Fri Oct 17 2014 01:01:01 GMT-0300
Sat Oct 18 2014 01:01:01 GMT-0300
Sun Oct 19 2014 01:01:01 GMT-0200
Mon Oct 20 2014 01:01:01 GMT-0200

Results in a string representation of tomorrow's date. Use new Date() to get today's date, adding one day using Date.getDate() and Date.setDate(), and converting the Date object to a string.

  const tomorrow = () => {
      let t = new Date();
      t.setDate(t.getDate() + 1);
      return `${t.getFullYear()}-${String(t.getMonth() + 1).padStart(2, '0')}-${String(
        t.getDate()
      ).padStart(2, '0')}`;
    };
    tomorrow();

Incrementing date's year with vanilla js:

start_date_value = "01/01/2019"
var next_year = new Date(start_date_value);
next_year.setYear(next_year.getYear() + 1);
console.log(next_year.getYear()); //=> 2020

Just in case someone wants to increment other value than the date (day)


Via native JS, to add one day you may do following:

let date = new Date(); // today
date.setDate(date.getDate() + 1) // tomorrow

Another option is to use moment library:

const date = moment().add(14, "days").toDate()

Timezone/daylight savings aware date increment for JavaScript dates:

function nextDay(date) {
    const sign = v => (v < 0 ? -1 : +1);
    const result = new Date(date.getTime());
    result.setDate(result.getDate() + 1);
    const offset = result.getTimezoneOffset();
    return new Date(result.getTime() + sign(offset) * offset * 60 * 1000);
}

I feel that nothing is safer than .getTime() and .setTime(), so this should be the best, and performant as well.

const d = new Date()
console.log(d.setTime(d.getTime() + 1000 * 60 * 60 * 24)) // MILLISECONDS

.setDate() for invalid Date (like 31 + 1) is too dangerous, and it depends on the browser implementation.