Incrementing a date in JavaScript

Question

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 v

Answer 1

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