title: new Date() sets wrong month
body: <p>I want to parse a string (or even the ints) at the <strong>new Date()</strong> function, but see what happens:</p>
  
  <pre><code>date = "2015-12-13"
  "2015-12-13"
  date
  "2015-12-13"
  date2 = new Date(date);
  Sat Dec 12 2015 19:00:00 GMT-0500 (Hora est. Pacífico, Sudamérica)
  date2 = new Date(2015,12,13);
  Wed Jan 13 2016 00:00:00 GMT-0500 (Hora est. Pacífico, Sudamérica)
  </code></pre>
  
  <p>what could be wrong?</p>