diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index a06bfe952d..7d4dc450dc 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -108,6 +108,20 @@ function get_lastpostdate() {
 	return $lastpostdate;
 }
 
+function get_lastpostmodified() {
+	global $tableposts, $cache_lastpostmodified, $use_cache, $pagenow, $wpdb;
+	if ((!isset($cache_lastpostmodified)) OR (!$use_cache)) {
+		$time_difference = get_settings('time_difference'); // for some weird reason the global wasn't set anymore?
+		$now = date("Y-m-d H:i:s",(time() + ($time_difference * 3600)));
+
+		$lastpostmodified = $wpdb->get_var("SELECT post_modified FROM $tableposts WHERE post_modified <= '$now' AND post_status = 'publish' ORDER BY post_modified DESC LIMIT 1");
+		$cache_lastpostmodified = $lastpostmodified;
+	} else {
+		$lastpostmodified = $cache_lastpostmodified;
+	}
+	return $lastpostmodified;
+}
+
 function user_pass_ok($user_login,$user_pass) {
 	global $cache_userdata,$use_cache;
 	if ((empty($cache_userdata[$user_login])) OR (!$use_cache)) {