diff --git a/bower.json b/bower.json
index 93dc32a..b0b13ff 100644
--- a/bower.json
+++ b/bower.json
@@ -1,7 +1,7 @@
 {
   "name": "strolch-wc-util-behavior",
   "description": "Strolch Polymer Util Behaviors",
-  "version": "0.3.4",
+  "version": "0.3.5",
   "authors": [
     "Robert von Burg"
   ],
diff --git a/strolch-wc-util-behavior.html b/strolch-wc-util-behavior.html
index 45debac..8b873eb 100644
--- a/strolch-wc-util-behavior.html
+++ b/strolch-wc-util-behavior.html
@@ -294,6 +294,11 @@
         //
         // Date Time functions
         //
+        formatDateTimeDashIfEmpty: function (string) {
+            if (string == null || string === "" || string === "-" || string === "1970-01-01T01:00:00+01:00")
+                return "-";
+            return Strolch.toLocalDateTime(string);
+        },
         formatDateTime: function (string) {
             return Strolch.toLocalDateTime(string);
         },