diff --git a/ReflexUtils.ftl b/ReflexUtils.ftl
index 574d0a2..d033bfb 100644
--- a/ReflexUtils.ftl
+++ b/ReflexUtils.ftl
@@ -2,7 +2,7 @@
 <#-- Concat reflex timestamp with reflex time zone and format this date in ISO UTC format -->
 <#-- --------------------------------------------------------------------------------------- -->
 <#function RfxDateTimetoUTC rfxdatetime offset >
-  <#return (rfxdatetime?datetime("yyyy-MM-dd'T'HH:mm:ss")?iso_utc)>
+  <#return ((rfxdatetime + offset)?datetime.iso?iso_utc)>
 </#function>
 
 <#-- --------------------------------------------------------------------------------------- -->