title: (Transact-SQL) DATEDIFF and leap years
body: <p>I have a problem with DATEDIFF function.</p>
  
  <p>My date format is <code>dd/mm/yyyy</code>.</p>
  
  <p><code>@START_DATE = 01/02/2004</code><BR>
  <code>@END_DATE = 29/01/2014</code></p>
  
  <p>The query <code>(DATEDIFF(DAY,@START_DATE,@END_DATE) / 365)</code> return <code>10</code>, but the number of correct years is <code>9</code>. This happens because my query does not consider leap years.</p>
  
  <p><br>
  What I can do to keep an accurate count?
  Thanks.</p>