title: How to calculate the number of years between 2 dates?
body: <p>I would like to compare 2 dates to confirm that the number of years between is <code>&gt;= 18</code>. For example, if my 2 dates are <code>03-12-2011</code> and <code>03-12-1983</code> then this should pass validation, however, if my 2 dates are <code>03-12-2011</code> and <code>03-12-1995</code> then this should fail validation.</p>
  
  <p>Can anyone help me?</p>