Try setting date format explicitly

Author: DavidMStraub

tests/test_endpoints/test_timelines.py

@@ -22,6 +22,8 @@
 
 import unittest
 
+from gramps.gen.utils.config import config
+
 from . import BASE_URL, get_test_client
 from .checks import (
     check_conforms_to_schema,
@@ -45,6 +47,9 @@ class TestTimelinesPeople(unittest.TestCase):
     @classmethod
     def setUpClass(cls):
         """Test class setup."""
+
+        config.set("preferences.date-format", 0)
+
         cls.client = get_test_client()
 
     def test_get_timelines_people_requires_token(self):