title: how do I get the EXACT number of months between two dates?
body: <pre><code>DATEDIFF(MONTH, '1/1/2014', '12/31/2014') + 1
  </code></pre>
  
  <p>This will give me 12.</p>
  
  <p>What if I do this:</p>
  
  <pre><code>DATEDIFF(MONTH, '1/1/2014', '12/30/2014') + 1
  </code></pre>
  
  <p>It should give me 11 point something. How do I go about getting the exact number of months between these two dates? This needs to work for any combination of dates (any month of the year for any year).</p>