title: WHERE clause on 'date' column
body: <p>I've got table with column of type <code>date</code>. In my script, I generate <code>date</code> array as follows :</p>
  
  <pre><code>$date2 = date('Y-d-m', strtotime($date2));
  for ($i = 0; $i &lt;= 7; $i++)
  {
      $date1 = str_replace('-', '/', $date2);
      $tomorrow = date('Y-d-m',strtotime($date1 . "+".$i." days"));
  
      echo 'counted date : '.$tomorrow.PHP_EOL ;
      array_push($dates, $tomorrow);
  }
  </code></pre>
  
  <p>And got the following output :</p>
  
  <pre><code>counted date : 2016-01-08
  counted date : 2016-02-08
  counted date : 2016-03-08
  counted date : 2016-04-08
  counted date : 2016-05-08
  counted date : 2016-06-08
  counted date : 2016-07-08
  counted date : 2016-08-08
  </code></pre>
  
  <p>I also got Phalcon expression :</p>
  
  <pre><code>$status1 = $app
      -&gt;modelsManager
      -&gt;executeQuery("
          SELECT * 
            FROM MastersFullTime 
           WHERE MastersFullTime.date = :date:
             AND MastersFullTime.master_id = :master_id:"
          ,
          array(
              'date' =&gt; $date , 
              'master_id' =&gt; $master_id
          )
      );
  </code></pre>
  
  <p>But <code>WHERE MastersFullTime.date = :date:</code> not working. How can I compare <code>date</code> objects? Thanks in advance! </p>