title: Add months to a date is not working in JavaScript
body: <p>I just want to add 45 months to the given date in JavaScript. I
   have tried this:</p>
  
  <pre><code>var startDateFormat = new Date(2018, 11, 24); // 11 is for January starts from 0
  var addDate = startDateFormat.setMonth(startDateFormat.getMonth() + 45); //want to add 45 months
  console.log(new Date(addDate).getFullYear() + "-" + new Date(addDate).getMonth() + 1 + "-" + new Date(addDate).getUTCDate())
  </code></pre>
  
  <p>But the result is 2019-101-23.
  Can anybody help me why this is happening?</p>