--- a/TZTimestamp.st	Thu May 24 17:49:38 2018 +0200
+++ b/TZTimestamp.st	Thu May 24 17:49:51 2018 +0200
@@ -120,7 +120,11 @@
 !TZTimestamp methodsFor:'accessing'!
 
 isLocalTimestamp
+    "return true, if I am a local timestamp (i.e. with no TZ info)"
+
     ^ false
+
+    "Modified (comment): / 24-05-2018 / 17:29:26 / Claus Gittinger"
 !
 
 timeInfo
@@ -200,6 +204,16 @@
     ^ Timestamp
 ! !
 
+!TZTimestamp methodsFor:'testing'!
+
+isTZTimestamp
+    "return true, if I am a timestamp with TZ info"
+
+    ^ true
+
+    "Created: / 24-05-2018 / 17:30:38 / Claus Gittinger"
+! !
+
 !TZTimestamp class methodsFor:'documentation'!
 
 version