title: Trying to format Google App Engine DateTimeProperty with a template modifier
body: <p>Well, I've a database model with a datetime field of type DateTimeProperty(). I want to format this value in my template, so I'm using:</p>
  
  <pre>{{row.datetime|date:'M j, H:i'}}</pre>
  
  <p>But Google App Engine throws this exception:</p>
  
  <pre>Traceback (most recent call last):
    File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/webapp/__init__.py", line 515, in __call__
      handler.get(*groups)
    File "/base/data/home/apps/.../1.348530548823349202/main.py", line 22, in get
      'nominations': row.nominations} for row in data]
    File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/webapp/template.py", line 155, in render
      t = load(template_path, debug)
    File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/webapp/template.py", line 183, in load
      template = django.template.loader.get_template(file_name)
    File "/base/python_runtime/python_lib/versions/third_party/django-0.96/django/template/loader.py", line 80, in get_template
      template = get_template_from_string(source, origin, template_name)
    File "/base/python_runtime/python_lib/versions/third_party/django-0.96/django/template/loader.py", line 88, in get_template_from_string
      return Template(source, origin, name)
    File "/base/python_runtime/python_lib/versions/third_party/django-0.96/django/template/__init__.py", line 158, in __init__
      self.nodelist = compile_string(template_string, origin)
    File "/base/python_runtime/python_lib/versions/third_party/django-0.96/django/template/__init__.py", line 174, in compile_string
      return parser.parse()
    File "/base/python_runtime/python_lib/versions/third_party/django-0.96/django/template/__init__.py", line 273, in parse
      compiled_result = compile_func(self, token)
    File "/base/python_runtime/python_lib/versions/third_party/django-0.96/django/template/defaulttags.py", line 544, in do_for
      nodelist_loop = parser.parse(('endfor',))
    File "/base/python_runtime/python_lib/versions/third_party/django-0.96/django/template/__init__.py", line 254, in parse
      filter_expression = self.compile_filter(token.contents)
    File "/base/python_runtime/python_lib/versions/third_party/django-0.96/django/template/__init__.py", line 338, in compile_filter
      return FilterExpression(token, self)
    File "/base/python_runtime/python_lib/versions/third_party/django-0.96/django/template/__init__.py", line 558, in __init__
      raise TemplateSyntaxError, "Could not parse the remainder: %s" % token[upto:]
  TemplateSyntaxError: Could not parse the remainder: :'M j, H:i'</pre>
  
  <p>What am I doing wrong?</p>
  
  <p>Thank you in advance.</p>