test: fix ScheduleFactory

program/tests/factories.py

-from datetime import timedelta
+from datetime import date, time, timedelta
 
 from factory import Sequence, post_generation
 from factory.django import DjangoModelFactory
@@ -100,9 +100,9 @@ class ScheduleFactory(DjangoModelFactory):
     class Meta:
         model = Schedule
 
-    end_time = "03:00:00"
-    first_date = "2023-01-01"
-    start_time = "02:00:00"
+    end_time = time(3, 0, 0)
+    first_date = date(2023, 1, 1)
+    start_time = time(2, 0, 0)
 
 
 class TimeslotFactory(DjangoModelFactory):