Index: django/contrib/syndication/feeds.py
===================================================================
--- django/contrib/syndication/feeds.py	(revision 9699)
+++ django/contrib/syndication/feeds.py	(working copy)
@@ -144,7 +144,7 @@
                 author_email = author_link = None
 
             pubdate = self.__get_dynamic_attr('item_pubdate', item)
-            if pubdate:
+            if pubdate and not pubdate.tzinfo:
                 now = datetime.now()
                 utcnow = datetime.utcnow()