title: Count months between two timestamp on postgresql?
body: <p>I want to count the number of months between two dates.</p>
  
  <p>Doing :</p>
  
  <pre><code>SELECT TIMESTAMP '2012-06-13 10:38:40' - TIMESTAMP '2011-04-30 14:38:40';
  </code></pre>
  
  <p>Returns : 
      0 years 0 mons 409 days 20 hours 0 mins 0.00 secs</p>
  
  <p>and so:  </p>
  
  <pre><code>SELECT extract(month from TIMESTAMP '2012-06-13 10:38:40' - TIMESTAMP '2011-04-30 14:38:40');
  </code></pre>
  
  <p>returns 0.</p>