diff --git a/SAS/TMSS/src/tmss/tmssapp/models/specification.py b/SAS/TMSS/src/tmss/tmssapp/models/specification.py
index 7d98fdc123cf9dc29fc93055904ccb5f6e637ace..6b21c1512c76f804399afed4ae448be2678a4297 100644
--- a/SAS/TMSS/src/tmss/tmssapp/models/specification.py
+++ b/SAS/TMSS/src/tmss/tmssapp/models/specification.py
@@ -662,7 +662,9 @@ class TaskBlueprint(NamedCommon):
 
     @property
     def relative_start_time(self) -> datetime.timedelta:
-        '''return the earliest relative start time of all subtasks of this task
+        '''The relative start time is relative to the start time of the 'start' of the parent scheduling unit.
+        It's based on the scheduling_relation's from the scheduling_unit's specification,
+        and hence it determines the order in which the tasks within the unit should be executed.
         '''
         scheduling_relations = list(self.first_scheduling_relation.all()) + list(self.second_scheduling_relation.all())
         for scheduling_relation in scheduling_relations:
@@ -679,11 +681,12 @@ class TaskBlueprint(NamedCommon):
                     # todo: max of several relations
                     if previous_related_task_blueprint.relative_stop_time:
                         return previous_related_task_blueprint.relative_stop_time + datetime.timedelta(seconds=time_offset)
-        return datetime.timedelta(seconds=666660)
+        return datetime.timedelta(seconds=0)
 
     @property
     def relative_stop_time(self) -> datetime.timedelta:
-        '''return the latest relative stop time of all subtasks of this task
+        '''The relative_stop_time is the relative_start_time+duration.
+        See relative_start_time for an explanation of it's intended usage.
         '''
         # todo: when it was added, check if subtask.specifications_template.type.value == TaskType.Choices.OBSERVATION.value:
         try: