title: (Yii)Datetime Validation fails
body: <p>I'd like to validate form input that is datetime for article to be posted.</p>
  
  <pre><code>$model = new Post('update');
      $model-&gt;attributes = $_POST['Post'];
  
          if($model-&gt;validate()){
  
              //But, validation fails...    
  
          }
  </code></pre>
  
  <p>This is the rule that I got to check if the input is datetime format or not.
  I used this page(<a href="http://chris-backhouse.com/date-validation-in-yii/528" rel="nofollow">http://chris-backhouse.com/date-validation-in-yii/528</a>) as reference.</p>
  
  <p>But I get validation error for 'created'input.</p>
  
  <pre><code>public function rules()
  {
      return array(
  
          //datetime validation
          array('created', 'date', 'message' =&gt; '{attribute}: is not a datetime!', 'format' =&gt; 'YYYY-MM-DD HH:MM:SS'),
  
          );
  }
  </code></pre>
  
  <p>This is what I have in $models-attribute.</p>
  
  <pre><code>array(1) { ["created"]=&gt; string(19) "2013-08-01 00:00:01" }
  </code></pre>
  
  <p>Could anyone knows how to make this work?</p>
  
  <p>Thanks a lot in advance!!!</p>