Index: wp-includes/SimplePie/Parse/Date.php
===================================================================
--- wp-includes/SimplePie/Parse/Date.php	(revision 29468)
+++ wp-includes/SimplePie/Parse/Date.php	(working copy)
@@ -173,7 +173,7 @@
 		'aug' => 8,
 		'august' => 8,
 		'sep' => 9,
-		'september' => 8,
+		'september' => 9,
 		'oct' => 10,
 		'october' => 10,
 		'nov' => 11,