Index: wp-admin/includes/class-wp-posts-list-table.php
===================================================================
--- wp-admin/includes/class-wp-posts-list-table.php	(revision 25389)
+++ wp-admin/includes/class-wp-posts-list-table.php	(working copy)
@@ -298,7 +298,7 @@
 			'title'    => 'title',
 			'parent'   => 'parent',
 			'comments' => 'comment_count',
-			'date'     => array( 'date', true )
+			'date'     => 'date'
 		);
 	}