diff --git a/examples/example.f90 b/examples/example.f90
index 8122c43e02f4fc5a64339c38ea861f0987783b4a..08e2e0dd42abaff45552b78c3e0e28271e0c69f0 100644
--- a/examples/example.f90
+++ b/examples/example.f90
@@ -23,12 +23,16 @@ program example
   type(datetime), pointer :: stop_date 
 
   type(timedelta), pointer :: time_step
+  type(timedelta), pointer :: td_one_hour
 
   type(datetime), pointer :: current_date 
  
   type(datetime), pointer :: current_date_test
   type(datetime), pointer :: tmp_date_test_1
   type(datetime), pointer :: dt
+  type(datetime), pointer :: dt_mw
+
+  
 
   ! setup of calendar
 
@@ -108,6 +112,25 @@ program example
   call event_tests
 
   call icon_tests
+
+  td_one_hour => newTimeDelta('-',0,0,0,1,0,0,0)
+
+  dt_mw => newDateTime("2015-03-01T00:00:00Z")
+
+  call timedeltaToString(td_one_hour, time_step_string)
+  print *, 'time delta -1 hour  : ', trim(time_step_string)
+
+
+  call datetimeToString(dt_mw, current_date_string)
+  print *, 'datetime 2015-03-01  : ', trim(current_date_string)
+
+  dt_mw = dt_mw + td_one_hour
+
+  call datetimeToString(dt_mw, current_date_string)
+  print *, 'datetime 2015-03-01 minus 1 hour  : ', trim(current_date_string)
+
+  call deallocateTimeDelta(td_one_hour)
+
   
   ! reset calendar