Q:

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? 

A:

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();

A:

var myDate = new Date();

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

A:

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);

