diff --git a/src/lib/time/timevalue.hpp b/src/lib/time/timevalue.hpp
index dfda0009a..1a230f605 100644
--- a/src/lib/time/timevalue.hpp
+++ b/src/lib/time/timevalue.hpp
@@ -261,6 +261,8 @@ namespace time {
   
   
   
+  class TimeSpan;
+  
   /**
    * Duration is the internal Lumiera time metric.
    * It is an absolute (positive) value, but can be
@@ -277,6 +279,12 @@ namespace time {
         : Offset(distance.abs())
         { }
       
+      explicit
+      Duration (Time const& timeSpec)
+        : Offset(Offset(timeSpec).abs())
+        { }
+      
+      Duration (TimeSpan const& interval);
       Duration (ulong count, FrameRate const& fps);
       
       static const Duration NIL;
@@ -307,13 +315,14 @@ namespace time {
         { }
                                                 ///////////TODO creating timespans needs to be more convenient....
       
-      operator Duration()  const 
+      Duration
+      duration()  const 
         {
           return dur_;
         }
       
       Time
-      getEnd()  const
+      end()  const
         {
           TimeVar startPoint (*this);
           return (startPoint + dur_);
@@ -381,6 +390,11 @@ namespace time {
          :                  raw;
   }
   
+  inline
+  Duration::Duration (TimeSpan const& interval)
+    : Offset(interval.duration())
+    { }
+  
   inline
   FrameRate::FrameRate (uint fps)
     : IFrac (__ensure_nonzero(fps))
diff --git a/tests/lib/time/time-value-test.cpp b/tests/lib/time/time-value-test.cpp
index d504197d5..ddc026b9d 100644
--- a/tests/lib/time/time-value-test.cpp
+++ b/tests/lib/time/time-value-test.cpp
@@ -248,6 +248,13 @@ namespace test{
           CHECK (distance > zero);
           CHECK (distance == backwards.abs());
           
+          Duration len1(Time(23,4,5,6));
+          CHECK (len1 == Time(FSecs(23,1000)) + Time(4 + 5*60 + 6*3600));
+          
+          Duration len2(Time(-10)); // negative specs...
+          CHECK (len2 == Time(10));//
+          CHECK (len2 > zero);    //   will be taken absolute
+          
           Duration unit(50, FrameRate::PAL);
           CHECK (Time(2) == unit);              // duration of 50 frames at 25fps is... (guess what)
           
@@ -275,7 +282,7 @@ namespace test{
           TimeValue zero;
           TimeValue five(5);
           
-          TimeSpan interval (Time(org), Duration(Offset (org,five)));        /////////////TODO need more convenient constructors
+          TimeSpan interval (Time(org), Duration(Offset (org,five)));
           
           // the time span behaves like a time
           CHECK (org == interval);
@@ -285,11 +292,16 @@ namespace test{
           Duration theLength(interval);
           CHECK (theLength == Offset(org,five).abs());
           
-          Time endpoint = interval.getEnd();
-          CHECK (Offset(interval,endpoint) == Offset(org,five).abs());
+          Time endpoint = interval.end();
+          TimeSpan successor (endpoint, Duration(Time(2)));
           
-          cout << "Interval: " << interval 
-               << " Endpoint: " << endpoint << endl; 
+          CHECK (Offset(interval,endpoint) == Offset(org,five).abs());
+          CHECK (Offset(endpoint,successor.end()) == Duration(successor));
+          
+          cout <<   "Interval-1: " << interval 
+               << "  Interval-2: " << successor 
+               << "  End point: "  << successor.end()
+               << endl; 
         }
     };