title: Setting "time" or DateInterval with Doctrine
body: <p>I inherited from a MySQL DB with a "time" column representing a "time in the week" in the range from "00:00:00" to "167:59:59" (24*7 = 168).</p>
  
  <p>The corresponding ORM declaration is :</p>
  
  <pre><code> * @var \DateTime $startTime
   * @ORM\Column(name="startTime", type="interval")
  </code></pre>
  
  <p>Apparently Doctrine always uses DateTime (not DateInterval) with PHP, probably to keep compatible with other DB engines.</p>
  
  <p><strong>Problem is</strong> : I fail to understand how to set those values, as they always turn to NULL on persist.</p>
  
  <p>For instance : </p>
  
  <pre><code>$pWeek-&gt;setEndTime(new \DateTime('T'06:00:00'));
  </code></pre>
  
  <p>will set a DateTime in the Entity, but NULL in database.</p>
  
  <p>I think the guys who designed this have set the data directly in DB, but since there's an ORM, I need to be able to set data with it.</p>