date validation: bugfix

process/Date_lib/process.js

@@ -15,12 +15,11 @@ function DateUtils() {}
  * @param pStart {Number}
  * @param pEnd {Number}
  * 
- * @result {Boolean|null} Boolean if it was able to check smth or null if the input values were not valid
+ * @result {Boolean} Boolean if it was able to check. True if one of them is null / "" because this should be checked by mandatory if needed.
  */
 DateUtils.validateBeginnBeforeEnd = function(pStart, pEnd) {
     if (!pStart || !pEnd) 
-        return null;
-    
+        return true;
     return pStart <= pEnd;
 }