title: zend date validation error
body: <p>I am using a Zend form for my web site. There is a date field present for dob.</p>
  
  <pre><code> $date_of_birth      = $this-&gt;createElement('text','date_of_birth')
                          -&gt; setAttrib('class','txt_feeld')
                          -&gt; setAttrib('placeholder', 'dd-mm-yyyy')
                          -&gt; setRequired(true);   
      $date_of_birth      -&gt; addValidator('NotEmpty', true)
                          -&gt; getValidator('NotEmpty')-&gt;setMessage('Enter date of birth');
      $date_of_birth      -&gt; addValidator('date',true, array('dd-mm-yyyy'))
                          -&gt; getValidator('date')-&gt;setMessage('Invalid Date');
      $date_of_birth      -&gt; setDecorators(array('ViewHelper','Errors'));
  </code></pre>
  
  <p>After enter this date format 'dd-mm-yy' i want to generate a error message. Because i validate the date like this format  dd-mm-yyyy. But i can't getting error message.</p>
  
  <p>if anything wrong in this code. please help me.  </p>