diff --git a/backend/timed/tracking/serializers.py b/backend/timed/tracking/serializers.py
index 56080bea6..b2603cf3a 100644
--- a/backend/timed/tracking/serializers.py
+++ b/backend/timed/tracking/serializers.py
@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from datetime import date, timedelta
+from datetime import date, time, timedelta
 from typing import TYPE_CHECKING
 
 from django.contrib.auth import get_user_model
@@ -108,8 +108,13 @@ def validate(self, data):
         from_time = data.get("from_time", instance and instance.from_time)
         to_time = data.get("to_time", instance and instance.to_time)
 
-        # validate that to is not before from
-        if to_time is not None and to_time < from_time:
+        if to_time == from_time:
+            raise ValidationError(
+                _("An attendance may not start and end at the same time.")
+            )
+
+        # allow attendances to end at midnight (00:00)
+        if to_time < from_time and to_time != time(0, 0):
             raise ValidationError(_("An attendance may not end before it starts."))
 
         return data
diff --git a/backend/timed/tracking/tests/test_attendance.py b/backend/timed/tracking/tests/test_attendance.py
index 6636236b5..25fdc82fb 100644
--- a/backend/timed/tracking/tests/test_attendance.py
+++ b/backend/timed/tracking/tests/test_attendance.py
@@ -104,17 +104,47 @@ def test_attendance_delete(internal_employee_client):
     assert response.status_code == status.HTTP_204_NO_CONTENT
 
 
-def test_attendance_to_before_from(internal_employee_client, attendance_factory):
-    """Test that to is not before from."""
-    attendance = attendance_factory(
-        user=internal_employee_client.user, from_time=time(7, 30), to_time=time(8, 30)
-    )
+@pytest.mark.parametrize(
+    (
+        "attendance__from_time",
+        "attendance__to_time",
+        "set_from_time",
+        "set_to_time",
+        "error",
+    ),
+    [
+        (time(7, 30), time(8, 30), "07:30", "08:30", None),
+        (time(7, 30), time(8, 30), "07:30", "00:00", None),
+        (
+            time(7, 30),
+            time(8, 30),
+            "07:30",
+            "07:00",
+            "An attendance may not end before it starts.",
+        ),
+        (
+            time(7, 30),
+            time(8, 30),
+            "07:30",
+            "07:30",
+            "An attendance may not start and end at the same time.",
+        ),
+    ],
+)
+def test_attendance_validation(
+    internal_employee_client, attendance, set_from_time, set_to_time, error
+):
+    attendance.user = internal_employee_client.user
+    attendance.save()
 
     data = {
         "data": {
             "type": "attendances",
             "id": attendance.id,
-            "attributes": {"to-time": "07:00"},
+            "attributes": {
+                "to-time": set_to_time,
+                "from-time": set_from_time,
+            },
         }
     }
 
@@ -122,8 +152,9 @@ def test_attendance_to_before_from(internal_employee_client, attendance_factory)
 
     res = internal_employee_client.patch(url, data)
 
-    assert res.status_code == status.HTTP_400_BAD_REQUEST
-    json = res.json()
-    assert json["errors"][0]["detail"] == (
-        "An attendance may not end before it starts."
-    )
+    status_code = status.HTTP_400_BAD_REQUEST if error else status.HTTP_200_OK
+    assert res.status_code == status_code
+
+    if error:
+        json = res.json()
+        assert json["errors"][0]["detail"] == error