title: Django make_aware usage
body: <p><a href="https://docs.djangoproject.com/en/1.11/ref/utils/#django.utils.timezone.make_aware" rel="noreferrer">Django docs</a> says:</p>
  
  <blockquote>
    <p>The <code>pytz.NonExistentTimeError</code> exception is raised if you try to make
    <code>value</code> aware during a DST transition such that the time never occurred
    (when entering into DST). Setting <code>is_dst</code> to <code>True</code> or <code>False</code> will avoid
    the exception by moving the hour backwards or forwards by 1
    respectively. For example, <code>is_dst=True</code> would change a non-existent
    time of 2:30 to 1:30 and <code>is_dst=False</code> would change the time to 3:30.</p>
  </blockquote>
  
  <p>So I expect the time to be shifted one forward or backward depending on the value of <code>is_dst</code>.</p>
  
  <p>But from my tests, the timezone is being shifted, not the time. Am I misunderstanding the Django docs or this is a bug ?</p>
  
  <p>I tested the following :</p>
  
  <pre><code>import pytz
  import datetime
  from django.utils.timezone import make_aware
  
  tz = pytz.timezone('America/Sao_Paulo')
  dt = datetime.datetime(2017, 10, 15 ,0 ,0)
  print(make_aware(dt, tz))        # NonExistentTimeError
  print(make_aware(dt, tz, True))  # 2017-10-15 00:00:00-02:00
  print(make_aware(dt, tz, False)) # 2017-10-15 00:00:00-03:00
  </code></pre>
  
  <p>2017-10-15 is when DST will begin in that <code>America/Sao_Paulo</code> timezone, so when the clock reaches 00:00 it should jump to 01:00. The datetimes returned by the <code>make_aware</code> method are inexistent.</p>