diff --git a/SAS/TMSS/backend/test/t_reservations.py b/SAS/TMSS/backend/test/t_reservations.py
index 3ad322f2f1150a10e25a86d3077961275c20a016..e44e64aa9055df3642983a8520286fe6ea887459 100755
--- a/SAS/TMSS/backend/test/t_reservations.py
+++ b/SAS/TMSS/backend/test/t_reservations.py
@@ -255,15 +255,51 @@ class TestStationReservations(unittest.TestCase):
         task_spec['station_groups'] = [{'stations': ['CS001', 'RS205'], 'max_nr_missing': 0}]
         scheduling_unit_blueprint = models.SchedulingUnitBlueprint.objects.create(**SchedulingUnitBlueprint_test_data(specifications_template=models.SchedulingUnitTemplate.objects.get(name='scheduling unit')))
         task_blueprint = models.TaskBlueprint.objects.create(**TaskBlueprint_test_data(specifications_template=task_template, scheduling_unit_blueprint=scheduling_unit_blueprint, specifications_doc=task_spec))
-        subtask = models.Subtask.objects.create(**Subtask_test_data(subtask_template=subtask_template, specifications_doc=spec, task_blueprint=task_blueprint))
+        subtask = models.Subtask.objects.create(**Subtask_test_data(subtask_template=subtask_template, specifications_doc=spec, task_blueprint=task_blueprint,
+                                                                    scheduled_on_sky_start_time=datetime(2020, 1, 1, 10, 0, 0), scheduled_on_sky_stop_time=datetime(2020, 1, 1, 14, 0, 0)))
         set_subtask_state_following_allowed_transitions(subtask, "started")
 
-        # try to create a reservation and assert failure
+        # try to create a reservation that overlaps with the subtask and assert failure
+        #
+        # full overlap
         with self.assertRaises(ValueError) as context:
-            self.create_station_reservation("my-reservation", ["CS002", "RS205", "DE609"], datetime(2020, 1, 1, 0, 0, 0), datetime(2020, 1, 2, 0, 0, 0))
+            self.create_station_reservation("my-reservation-long", ["CS002", "RS205", "DE609"], datetime(2020, 1, 1, 0, 0, 0), datetime(2020, 1, 2, 0, 0, 0))
         self.assertIn("Station(s) ['RS205'] cannot be reserved", str(context.exception))
         self.assertIn(scheduling_unit_blueprint.name, str(context.exception))
 
+        with self.assertRaises(ValueError) as context:
+            self.create_station_reservation("my-reservation-short", ["CS002", "RS205", "DE609"], datetime(2020, 1, 1, 11, 0, 0), datetime(2020, 1, 1, 13, 0, 0))
+        self.assertIn("Station(s) ['RS205'] cannot be reserved", str(context.exception))
+        self.assertIn(scheduling_unit_blueprint.name, str(context.exception))
+
+        # partial overlap
+        with self.assertRaises(ValueError) as context:
+            self.create_station_reservation("my-reservation-early", ["CS002", "RS205", "DE609"], datetime(2020, 1, 1, 0, 0, 0), datetime(2020, 1, 1, 12, 0, 0))
+        self.assertIn("Station(s) ['RS205'] cannot be reserved", str(context.exception))
+        self.assertIn(scheduling_unit_blueprint.name, str(context.exception))
+
+        with self.assertRaises(ValueError) as context:
+            self.create_station_reservation("my-reservation-late", ["CS002", "RS205", "DE609"], datetime(2020, 1, 1, 12, 0, 0), datetime(2020, 1, 2, 0, 0, 0))
+        self.assertIn("Station(s) ['RS205'] cannot be reserved", str(context.exception))
+        self.assertIn(scheduling_unit_blueprint.name, str(context.exception))
+
+        # open end
+        with self.assertRaises(ValueError) as context:
+            self.create_station_reservation("my-reservation-open-end", ["CS002", "RS205", "DE609"], datetime(2020, 1, 1, 0, 0, 0))
+        self.assertIn("Station(s) ['RS205'] cannot be reserved", str(context.exception))
+        self.assertIn(scheduling_unit_blueprint.name, str(context.exception))
+
+        # assert that it works before or after the subtask
+        #
+        # before
+        self.create_station_reservation("my-reservation-before", ["CS002", "RS205", "DE609"], datetime(2020, 1, 1, 0, 0, 0), datetime(2020, 1, 1, 9, 0, 0))
+
+        # after
+        self.create_station_reservation("my-reservation-after", ["CS002", "RS205", "DE609"], datetime(2020, 1, 1, 15, 0, 0), datetime(2020, 1, 2, 0, 0, 0))
+
+        # after, open end
+        self.create_station_reservation("my-reservation-open-end", ["CS002", "RS205", "DE609"], datetime(2020, 1, 1, 15, 0, 0))
+
 
 class CreationFromReservationStrategyTemplate(unittest.TestCase):
     """