TMSS-687: Fixed the date to check

SAS/TMSS/backend/test/t_tmssapp_specification_django_API.py

@@ -948,12 +948,12 @@ class TestStationTimeLine(unittest.TestCase):
             models.StationTimeline.objects.create(**test_data)
             self.assertIn('unique_station_time_line', str(context.exception))
 
-        self.assertEqual(len(models.StationTimeline.objects.filter(timestamp=datetime.date.today())), 1)
+        self.assertEqual(len(models.StationTimeline.objects.filter(timestamp=datetime.date(2021, 4, 1))), 1)
         self.assertEqual(len(models.StationTimeline.objects.all()), 1)
         # Add a non-duplicate
         test_data["station_name"] = "CS002"
         models.StationTimeline.objects.create(**test_data)
-        self.assertEqual(len(models.StationTimeline.objects.filter(timestamp=datetime.date.today())), 2)
+        self.assertEqual(len(models.StationTimeline.objects.filter(timestamp=datetime.date(2021, 4, 1))), 2)
         self.assertEqual(len(models.StationTimeline.objects.all()), 2)