--- a/Timestamp.st	Fri Jul 27 12:12:31 2018 +0200
+++ b/Timestamp.st	Fri Jul 27 12:13:09 2018 +0200
@@ -1040,7 +1040,7 @@
     |day month year dayOfYear monthAndDay
      hour minute second millisecond
      utcOffset inStream formatStream error fChar format itemHandler
-     len now s fractionString fraction picos ts|
+     len s fractionString fraction picos ts|
 
     error := [:msg |
                 exceptionalValue isBlock ifTrue:[
@@ -1206,7 +1206,7 @@
     ].
 
     year isNil ifTrue:[
-        year := (now := Timestamp now) year
+        year := Timestamp now year
     ].
     
     dayOfYear notNil ifTrue:[
@@ -1258,6 +1258,8 @@
      Timestamp readFrom:'20-2-1995 13:11:06.001' format:'%day-%month-%year %h:%m:%s.%f' language:nil onError:[self halt]
      Timestamp readFrom:'20-2-1995 13:11:06.12345' format:'%day-%month-%year %h:%m:%s.%f' language:nil onError:[self halt]
     "
+
+    "Modified: / 27-07-2018 / 11:57:59 / Stefan Vogel"
 !
 
 readFrom:aStringOrStream onError:exceptionBlock
@@ -1952,40 +1954,6 @@
 ! !
 
 
-!Timestamp methodsFor:'Compatibility-ST80'!
-
-hour
-    "return the hour (0..23).
-     ST-80 Timestamp compatibility 
-     (I'd prefer the name #hours, for Time compatibility)."
-
-    ^ self hours
-
-    "Created: 1.7.1996 / 15:14:50 / cg"
-    "Modified: 1.7.1996 / 15:15:32 / cg"
-!
-
-minute
-    "return the minute (0..59).
-     ST-80 Timestamp compatibility 
-     (I'd prefer the name #minutes, for Time compatibility)."
-
-    ^ self minutes
-
-    "Created: 1.7.1996 / 15:14:29 / cg"
-    "Modified: 1.7.1996 / 15:15:37 / cg"
-!
-
-second
-    "return the second (0..59).
-     ST-80 Timestamp compatibility 
-     (I'd prefer the name #seconds, for Time compatibility)."
-
-    ^ self seconds
-
-    "Created: 1.7.1996 / 15:14:19 / cg"
-    "Modified: 1.7.1996 / 15:15:49 / cg"
-! !
 
 !Timestamp methodsFor:'accessing'!
 
@@ -2619,9 +2587,9 @@
 millisecondDeltaFrom:aTimestamp
     "return the delta in milliseconds between 2 absolute times.
      The argument is supposed to be BEFORE the receiver,
-	computes self - aTimestamp"
-
-    ^ self getMilliseconds - (aTimestamp getMilliseconds)
+        computes self - aTimestamp"
+
+    ^ osTime - (aTimestamp getMilliseconds)
 
     "
      |t1 t2|
@@ -2633,6 +2601,7 @@
     "
 
     "Modified: / 10-07-2010 / 09:37:18 / cg"
+    "Modified: / 27-07-2018 / 10:34:11 / Stefan Vogel"
 !
 
 roundedToSecond
@@ -2889,7 +2858,8 @@
 
     ^ TZTimestamp new 
         osTime:osTime;
-        utcOffset:(anOffset asTimeDuration)  
+        utcOffset:(anOffset asTimeDuration);
+        yourself.
 
     "
      Timestamp now  -- now as local time
@@ -2900,6 +2870,8 @@
      Timestamp now utcOffset:(5 hours) -- now in Eastern time
      Timestamp now asTZTimestampInZone:'EST' -- now in Eastern time
     "
+
+    "Modified: / 27-07-2018 / 11:54:45 / Stefan Vogel"
 !
 
 utcSecondsSince1901
@@ -2918,6 +2890,21 @@
     "
 ! !
 
+!Timestamp methodsFor:'double dispatching'!
+
+differenceFromTimestamp:aTimestamp
+    |newMillis newPicos|
+
+    newMillis := aTimestamp getMilliseconds - osTime.
+    newPicos := (aTimestamp additionalPicoseconds) - (additionalPicoseconds ? 0).
+
+    ^ TimeDuration basicNew
+        setMilliseconds:newMillis additionalPicoseconds:newPicos.
+
+    "Created: / 27-07-2018 / 08:45:22 / Stefan Vogel"
+    "Modified (format): / 27-07-2018 / 10:50:05 / Stefan Vogel"
+! !
+
 !Timestamp methodsFor:'initialization'!
 
 UTCyear:y month:m day:d hour:h minute:min second:s millisecond:millis
@@ -3248,11 +3235,8 @@
     self isUtcTimestamp ifTrue:[
         asUTC := true. asLocal := false.
     ] ifFalse:[
-        self isLocalTimestamp ifTrue:[
-            asUTC := false. asLocal := true.
-        ] ifFalse:[
-            asUTC := false. asLocal := false.
-        ]
+        asUTC := false.
+        asLocal := self isLocalTimestamp.
     ].
 
     Timestamp::TimestampISO8601Builder
@@ -3288,6 +3272,7 @@
 
     "Created: / 24-05-2018 / 17:28:25 / Claus Gittinger"
     "Modified (comment): / 25-05-2018 / 12:00:14 / Claus Gittinger"
+    "Modified: / 27-07-2018 / 11:57:21 / Stefan Vogel"
 !
 
 printIso8601FormatOn:aStream timeSeparator:sepChar
@@ -3333,20 +3318,16 @@
     |asUTC asLocal|
 
     self isUtcTimestamp ifTrue:[
-	asUTC := true. asLocal := false.
+        asUTC := true. asLocal := false.
     ] ifFalse:[
-	self isLocalTimestamp ifTrue:[
-	    asUTC := false. asLocal := true.
-	] ifFalse:[
-	    asUTC := false. asLocal := false.
-	]
+        asLocal := self isLocalTimestamp.
     ].
 
     Timestamp::TimestampISO8601Builder
-	print:self compact:false
-	asLocal:asLocal asUTC:asUTC withMilliseconds:true
-	timeSeparator:(Character space)
-	on:aStream
+        print:self compact:false
+        asLocal:asLocal asUTC:asUTC withMilliseconds:true
+        timeSeparator:(Character space)
+        on:aStream
 
 "/    self printOn:aStream format:'%(year)-%(mon)-%(day) %h:%m:%s.%i'
 "/    self printOn:aStream format:'%(Day)-%(mon)-%(year) %h:%m:%s.%i'
@@ -3375,7 +3356,8 @@
      Date today printOn:Transcript. Transcript cr.
     "
 
-    "Modified: 1.7.1996 / 15:20:59 / cg"
+    "Modified: / 01-07-1996 / 15:20:59 / cg"
+    "Modified: / 27-07-2018 / 11:58:58 / Stefan Vogel"
 !
 
 printRFC1123FormatOn:aStream
@@ -3438,34 +3420,6 @@
     "
 !
 
-printStringIso8601Compressed
-    "return a printString as UTC in a format like 20141017T170939Z.
-     Notice: if the receiver is a UTCTimestamp, it is printed as 20141017T170939Z;
-     if it has timezone info attached (i.e. is a TZTimestamp), it is printed as 20141017T170939+01;
-     if it is a local timestamp (without any TZ info), it is printed as such: 20141017T170939"
-
-    ^ String streamContents:[:s | self printIso8601CompressedOn:s] 
-
-    "
-     Timestamp now printStringIso8601Compressed
-     TZTimestamp now printStringIso8601Compressed
-     UtcTimestamp now printStringIso8601Compressed
-     Timestamp now asUtcTimestamp printStringIso8601Compressed
-
-     Time now printStringIso8601Compressed
-
-     (Timestamp readFrom:'2018-05-24T17:26:40.271') printStringIso8601
-     (Timestamp readFrom:'2018-05-24T17:26:40.271+02') printStringIso8601
-     Timestamp now printStringIso8601
-     TZTimestamp now printStringIso8601
-     UtcTimestamp now printStringIso8601
-     Timestamp now asUtcTimestamp printStringIso8601
-    "
-
-    "Created: / 16-06-2005 / 16:11:31 / masca"
-    "Modified (comment): / 25-05-2018 / 12:02:18 / Claus Gittinger"
-!
-
 printStringRFC1123Format
     "return the RFC1123 representation of the receiver.
      This format is used in HTTP requests and looks like:
@@ -3641,7 +3595,7 @@
     "change the sub-second fractional part only (leaves everything above seconds unchanged)"
 
     self 
-        setMilliseconds:(self getMilliseconds // 1000) * 1000   "/ strip off any sub-second part 
+        setMilliseconds:(osTime // 1000) * 1000   "/ strip off any sub-second part 
         additionalPicoseconds:(aNumber * 1000000) truncated.    "/ set picos 
 
     "
@@ -3649,14 +3603,14 @@
      Timestamp now setMicrosecond:0.1   - 100 nanoseconds after the current second's start 
     "
 
-    "Modified (format): / 22-05-2018 / 16:53:26 / Stefan Vogel"
+    "Modified: / 27-07-2018 / 10:34:18 / Stefan Vogel"
 !
 
 setMillisecond:aNumber
     "change the sub-second fractional part only (leaves everything above seconds unchanged)"
 
     self 
-        setMilliseconds:(self getMilliseconds // 1000) * 1000       "/ strip off any sub-second part 
+        setMilliseconds:(osTime // 1000) * 1000       "/ strip off any sub-second part 
         additionalPicoseconds:(aNumber * 1000000000) truncated.     "/ set picos 
 
     "
@@ -3664,7 +3618,7 @@
      Timestamp now setMillisecond:0.05  - 50 microseconds after the current second's start
     "
 
-    "Modified (format): / 22-05-2018 / 16:53:38 / Stefan Vogel"
+    "Modified: / 27-07-2018 / 10:34:42 / Stefan Vogel"
 !
 
 setMilliseconds:millis
@@ -3705,13 +3659,15 @@
     "change the sub-second fractional part only (leaves everything above seconds unchanged)"
 
     self 
-        setMilliseconds:(self getMilliseconds // 1000) * 1000   "/ strip off any sub-second part
+        setMilliseconds:(osTime // 1000) * 1000   "/ strip off any sub-second part
         additionalPicoseconds:(aNumber * 1000) rounded.         "/ set picos
 
     "
      Timestamp now setNanosecond:15     - 15 nanoseconds after the current second's start
      Timestamp now setNanosecond:0.1    - 10 picoseconds after the current second's start
     "
+
+    "Modified: / 27-07-2018 / 10:34:52 / Stefan Vogel"
 !
 
 setSeconds:secs