title: Get max and min formatted date values from queryset in Django
body: <p>I have a one to many relation between <code>session</code> and <code>camp</code>. Now I have to get the max and min dates of all camps combined for a particular <code>session</code>.</p>
  <p>I am able to do it like this:</p>
  <pre><code>sess = Session.objects.last()
  max_min_dates = sess.camp.aggregate(Min('start_date'), Max('end_date'))
  </code></pre>
  <p>But if I try to send this from <code>HttpResponse</code> then I am getting this error:</p>
  <pre><code>TypeError: Object of type 'date' is not JSON serializable
  </code></pre>
  <p>So I need to send the formatted date values in that. How can I modify the above code to get the same?</p>