diff --git a/wp-includes/class-IXR.php b/wp-includes/class-IXR.php
index 01c3079d3b..7851b68a99 100644
--- a/wp-includes/class-IXR.php
+++ b/wp-includes/class-IXR.php
@@ -625,7 +625,7 @@ class IXR_Date {
         $this->timezone = substr($iso, 17);
     }
     function getIso() {
-        return $this->year.$this->month.$this->day.'T'.$this->hour.':'.$this->minute.':'.$this->second;
+        return $this->year.$this->month.$this->day.'T'.$this->hour.':'.$this->minute.':'.$this->second.$this->timezone;
     }
     function getXml() {
         return '<dateTime.iso8601>'.$this->getIso().'</dateTime.iso8601>';