title: django DateTimeField with UTC offset?
body: <p>I have a model with a DateTimeField:</p>
  
  <pre><code>deadline = models.DateTimeField(verbose_name="Valid unitl", null=True, blank=True)
  </code></pre>
  
  <p>Users should be allowed to input date, time and timezone info in the field. This is my desired format:  </p>
  
  <pre><code>2012-12-31 23:30 +0430
  </code></pre>
  
  <p>I expect the time will get converted to UTC before storing to db. So I tried using a model form for that, but it throws <code>Enter a valid date/time.</code> validation error on that DateTimeField if I enter the value above.</p>
  
  <p>This is in settings.py:</p>
  
  <pre><code>DATE_INPUT_FORMATS = ('%Y-%m-%d %H:%M %Z', )
  </code></pre>
  
  <p>What am I missing?</p>
  
  <p><strong>Edit:</strong></p>
  
  <p>As per Видул Петров's suggestion, tried to use a form field:</p>
  
  <pre><code>deadline2 = forms.DateTimeField(input_formats=['%Y-%m-%d %H:%M %Z',],
  </code></pre>
  
  <p>Got the same effect: <code>Enter a valid date/time.</code></p>
  
  <p><strong>Edit 2</strong></p>
  
  <p>It appears that datetime can't handle the "%z" parameter. This throws a ValueError:</p>
  
  <pre><code>datetime.datetime.strptime(value, format)
  </code></pre>
  
  <p>So I tested it in console:</p>
  
  <pre><code>&gt;&gt;&gt; import datetime
  &gt;&gt;&gt; datetime.datetime.strptime('2012-12-30 19:00 +0100', "%Y-%m-%d %H:%M %z")
  Traceback (most recent call last):
  File "&lt;console&gt;", line 1, in &lt;module&gt;
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_strptime.py", line 317, in _strptime
  (bad_directive, format))
  ValueError: 'z' is a bad directive in format '%Y-%m-%d %H:%M %z'
  </code></pre>
  
  <p>Also tried pytz:</p>
  
  <pre><code>&gt;&gt;&gt; import pytz
  &gt;&gt;&gt; pytz.datetime.datetime.strptime('2012-12-30 19:00 +0100', "%Y-%m-%d %H:%M %z")
  Traceback (most recent call last):
  File "&lt;console&gt;", line 1, in &lt;module&gt;
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_strptime.py", line 317, in _strptime
  (bad_directive, format))
  ValueError: 'z' is a bad directive in format '%Y-%m-%d %H:%M %z'
  </code></pre>
  
  <p>I really feel this should work. Did I miss some part of the docs that says otherwise?</p>