Index: wp-includes/functions.php
===================================================================
--- wp-includes/functions.php	(revision 11001)
+++ wp-includes/functions.php	(working copy)
@@ -1529,7 +1529,7 @@
 	$expiresOffset = 864000; // 10 days
 	header( "Content-Type: text/javascript; charset=" . get_bloginfo( 'charset' ) );
 	header( "Vary: Accept-Encoding" ); // Handle proxies
-	header( "Expires: " . gmdate( "D, d M Y H:i:s", time() + $expiresOffset ) . " GMT" );
+	header( "Expires: " . gmdate( "D, d M Y H:i:s", strtotime(gmdate("Y-m-d H:i:s")) + $expiresOffset ) . " GMT" );
 }
 
 /**