diff --git a/src/lib/time/time.cpp b/src/lib/time/time.cpp
index c39772fdf..996f1e07e 100644
--- a/src/lib/time/time.cpp
+++ b/src/lib/time/time.cpp
@@ -121,7 +121,7 @@ namespace time {
     { }
   
   
-  /** displaying an internal Lumiera Time value
+  /** display an internal Lumiera Time value
    *  for diagnostic purposes or internal reporting.
    * @warning internal Lumiera time values refer to an
    *         implementation dependent time origin/scale.
@@ -133,9 +133,28 @@ namespace time {
     return string (lumiera_tmpbuf_print_time (t_));
   }
   
-  TimeVar::operator string()  const
+  /** @note recommendation to use TCode for external representation */
+  TimeValue::operator string()  const
   {
-    return string (lumiera_tmpbuf_print_time (t_));
+    gavl_time_t time = t_;
+    int millis, seconds;
+    bool negative = (time < 0);
+    
+    if (negative) time = -time;
+    time /= GAVL_TIME_SCALE_MS;
+    millis = time % 1000;
+    seconds = time / 1000;
+    
+    return string (negative ? "-" : "")
+         + (seconds>0 or time==0? lexical_cast<string> (seconds)+"s" : "")
+         + (millis>0? lexical_cast<string> (millis)+"ms" : "")
+         ;
+  }
+  
+  TimeSpan::operator string()  const
+  {
+    return string (lumiera_tmpbuf_print_time (t_))
+                + "["+string(dur_)+"]";
   }
   
   
@@ -224,14 +243,10 @@ char*
 lumiera_tmpbuf_print_time (gavl_time_t time)
 {
   int milliseconds, seconds, minutes, hours;
-  int negative;
+  bool negative = (time < 0);
   
-  if(time < 0)
-    {
-      negative = 1;
+  if (negative)
       time = -time;
-    }
-  else negative = 0;
   
   time /= GAVL_TIME_SCALE_MS;
   milliseconds = time % 1000;
diff --git a/src/lib/time/timevalue.hpp b/src/lib/time/timevalue.hpp
index 04dec4370..d4585eb0c 100644
--- a/src/lib/time/timevalue.hpp
+++ b/src/lib/time/timevalue.hpp
@@ -118,6 +118,9 @@ namespace time {
       friend gavl_time_t _raw (TimeValue const& time) { return time.t_; }
       static TimeValue buildRaw_(gavl_time_t);
       
+      /** @internal diagnostics */
+      operator std::string ()  const;
+      
       // Supporting totally_ordered
       friend bool operator<  (TimeValue const& t1, TimeValue const& t2)  { return t1.t_ <  t2.t_; }
       friend bool operator<  (TimeValue const& t1, gavl_time_t t2)       { return t1.t_ <  t2   ; }
@@ -160,10 +163,7 @@ namespace time {
           return *this;
         }
       
-      /** @internal diagnostics */
-      operator std::string ()  const;
-      
-      // Supporting mixing with plain long int arithmetics
+      // Support mixing with plain long int arithmetics
       operator gavl_time_t ()  const { return t_; }
       
       // Supporting additive
@@ -515,6 +515,8 @@ namespace time {
       /** may change start / duration */
       void accept (Mutation const&);
       
+      /** @internal diagnostics */
+      operator std::string ()  const;
       
       /// Supporting extended total order, based on start and interval length
       friend bool operator== (TimeSpan const& t1, TimeSpan const& t2)  { return t1.t_==t2.t_ && t1.dur_==t2.dur_; }
diff --git a/tests/45controller.tests b/tests/45controller.tests
index 310c58ce8..abeff8e33 100644
--- a/tests/45controller.tests
+++ b/tests/45controller.tests
@@ -12,26 +12,26 @@ out: Command-State. arguments=unbound, ·noUNDO·.
 out: capture state...
 out: Command-State. arguments=Closure\(\), ·noUNDO·.
 out: Command-State. arguments=Closure\(.\), ·noUNDO·.
-out: Command-State. arguments=Closure\(.,0:..:....00\), ·noUNDO·.
-out: Command-State. arguments=Closure\(0:..:....00,glorious,..\), <mem: destruction>.
+out: Command-State. arguments=Closure\(.,.+s.*\), ·noUNDO·.
+out: Command-State. arguments=Closure\(.+s.*,glorious,..\), <mem: destruction>.
 out: would be serialised.....Command-State. arguments=Closure\(\), ·noUNDO·.
 out: would be serialised.....Command-State. arguments=Closure\(.\), ·noUNDO·.
-out: would be serialised.....Command-State. arguments=Closure\(.,0:..:....00\), ·noUNDO·.
-out: would be serialised.....Command-State. arguments=Closure\(0:..:....00,glorious,..\), <mem: destruction>.
+out: would be serialised.....Command-State. arguments=Closure\(.,.+s.*\), ·noUNDO·.
+out: would be serialised.....Command-State. arguments=Closure\(.+s.*,glorious,..\), <mem: destruction>.
 out: sizeof\( .+control1.ArgumentHolder.+ \) = .+
-out: Command-State. arguments=Closure\(0:..:....00,Lumiera rocks,..\), ·noUNDO·.
+out: Command-State. arguments=Closure\(.+s.*,Lumiera rocks,..\), ·noUNDO·.
 out: capture state...
 out: captured state: START...Lumiera rocks
-out: Command-State. arguments=Closure\(0:..:....00,Lumiera rocks,..\), <mem: START...Lumiera rocks>.
+out: Command-State. arguments=Closure\(.+s.*,Lumiera rocks,..\), <mem: START...Lumiera rocks>.
 out: invoke operation...
-out: START...doIt\( Time=0:..:....00 "Lumiera rocks" rand=.. \)
+out: START...doIt\( Time=.+s.* "Lumiera rocks" rand=.. \)
 out: undo... memento=START...Lumiera rocks
-out: START...doIt\( Time=0:..:....00 "Lumiera rocks" rand=.. \)undoIt\(time=0:..:....00\)----memento-:START...Lumiera rocks
+out: START...doIt\( Time=.+s.* "Lumiera rocks" rand=.. \)undoIt\(time=0:..:....00\)----memento-:START...Lumiera rocks
 out: capture state...
-out: modified: Command-State. arguments=Closure\(0:00:00.123,unbelievable,..\), <mem: START...doIt\( Time=0:..:....00 "Lumiera rocks" rand=.. \)undoIt\(time=0:..:....00\)----memento-:START...Lumiera rocksLumiera rocks>.
-out: copied  : Command-State. arguments=Closure\(0:..:....00,Lumiera rocks,..\), <mem: START...Lumiera rocks>.
-out: undo... memento=START...doIt\( Time=0:..:....00 "Lumiera rocks" rand=.. \)undoIt\(time=0:..:....00\)----memento-:START...Lumiera rocksLumiera rocks
-out: RESET...undoIt\(time=0:..:....00\)----memento-:START...doIt\( Time=0:..:....00 "Lumiera rocks" rand=.. \)undoIt\(time=0:..:....00\)----memento-:START...Lumiera rocksLumiera rocks
+out: modified: Command-State. arguments=Closure\(123ms,unbelievable,..\), <mem: START...doIt\( Time=.+s.* "Lumiera rocks" rand=.. \)undoIt\(time=0:..:....00\)----memento-:START...Lumiera rocksLumiera rocks>.
+out: copied  : Command-State. arguments=Closure\(.+s.*,Lumiera rocks,..\), <mem: START...Lumiera rocks>.
+out: undo... memento=START...doIt\( Time=.+s.* "Lumiera rocks" rand=.. \)undoIt\(time=0:..:....00\)----memento-:START...Lumiera rocksLumiera rocks
+out: RESET...undoIt\(time=0:..:....00\)----memento-:START...doIt\( Time=.+s.* "Lumiera rocks" rand=.. \)undoIt\(time=0:..:....00\)----memento-:START...Lumiera rocksLumiera rocks
 END
 
 
diff --git a/tests/basics/time/time-value-test.cpp b/tests/basics/time/time-value-test.cpp
index 057eb79ec..67667e3b1 100644
--- a/tests/basics/time/time-value-test.cpp
+++ b/tests/basics/time/time-value-test.cpp
@@ -319,7 +319,6 @@ namespace test{
           
           // the time span behaves like a time
           CHECK (org == interval);
-          CHECK (string(Time(org)) == string(interval));
           
           // can get the length by direct conversion
           Duration theLength(interval);