title: Django DST Time change issue with django datetimefield
body: <p>I am facing problem in my django app while working with <code>DateTimeField</code>.Its mainly because of DST time changes.</p>
  
  <p>I have created an event on 30-oct-2015(DST last week).
  I created a copy of first event which will be on 06-Nov-2015(Non DST day)</p>
  
  <p>I applied <code>timedelta</code> of 7 days , So it chaned days to 7+. But I did not aplly timedelta for hours.</p>
  
  <p>Due to Day Light saving , its reduced by <strong>one hour</strong>. I dont need this. I just want to have same hours. How Can I do that.?</p>
  
  <p>I tried with this , but did not help me.</p>
  
  <p><a href="https://stackoverflow.com/questions/26843987/dst-timezone-issue-in-django-app">DST timezone issue in django app</a></p>
  
  <p>Please see this screenshot
  <img src="https://i.stack.imgur.com/0Kjss.png" alt="enter image description here"></p>
  
  <p>my <code>models.py</code></p>
  
  <pre><code>from django.db import models
  from datetime import timedelta
  
  class Event(models.Model):
  
      name = models.CharField(max_length=100)
  
      created = models.DateTimeField(auto_now_add=True)
  
      start_date = models.DateTimeField()
  
      def __unicode__(self):
          return self.name
  
  
      def copy_event(self, add_days=timedelta(days=7)):
  
          start_date = self.start_date + add_days
          name = self.name +' (copy)'
          new_event = Event(name = name,created = self.created,start_date=start_date,)
  
          new_event.save()
  
          return new_event
  </code></pre>