Index: django/conf/__init__.py
===================================================================
--- django/conf/__init__.py	(revision 11227)
+++ django/conf/__init__.py	(working copy)
@@ -107,6 +107,10 @@
             # we don't do this unconditionally (breaks Windows).
             os.environ['TZ'] = self.TIME_ZONE
             time.tzset()
+            # Check whether the timezone is valid (Bug #3415)
+            utc_timezones = ('UTC','Universal','Zulu','Etc/UTC','Etc/Universal','Etc/Zulu')
+            if time.tzname == ('UTC', 'UTC') and self.TIME_ZONE not in utc_timezones:
+                raise ValueError(_("Incorrect timezone setting: %s") % self.TIME_ZONE)
 
     def get_all_members(self):
         return dir(self)