diff --git a/src/server/BreCal/database/sql_handler.py b/src/server/BreCal/database/sql_handler.py
index 2d85175..05c9296 100644
--- a/src/server/BreCal/database/sql_handler.py
+++ b/src/server/BreCal/database/sql_handler.py
@@ -33,7 +33,8 @@ def get_synchronous_shipcall_times_standalone(query_time:pd.Timestamp, all_df_ti
 
     returns: counts
     """
-    assert isinstance(query_time,pd.Timestamp)
+    assert isinstance(query_time,pd.Timestamp) or pd.isnull(query_time), f"expected query_time to be a pd.Timestamp or pd.NaT. Found: {type(query_time)}"
+    assert isinstance(all_df_times,pd.DataFrame)
 
     # get a timedelta for each valid (not Null) time entry
     time_deltas_eta = [(query_time.to_pydatetime()-time_.to_pydatetime()) for time_ in all_df_times.loc[:,"eta_berth"] if not pd.isnull(time_)]
@@ -439,4 +440,5 @@ class SQLHandler():
 
     def count_synchronous_shipcall_times(self, query_time:pd.Timestamp, all_df_times:pd.DataFrame, delta_threshold=900)->int:
         """count all times entries, which are too close to the query_time. The {delta_threshold} determines the threshold. returns counts (int)"""
+        assert isinstance(all_df_times, pd.DataFrame)
         return get_synchronous_shipcall_times_standalone(query_time, all_df_times, delta_threshold)
diff --git a/src/server/BreCal/validators/validation_rule_functions.py b/src/server/BreCal/validators/validation_rule_functions.py
index 24bbc62..693d253 100644
--- a/src/server/BreCal/validators/validation_rule_functions.py
+++ b/src/server/BreCal/validators/validation_rule_functions.py
@@ -929,6 +929,9 @@ class ValidationRuleFunctions(ValidationRuleBaseFunctions):
         query_time = times_agency.iloc[0].eta_berth
 
         # count the number of times, where a times entry is very close to the query time (uses an internal threshold, such as 15 minutes)
+        if all_times_agency is None:
+            all_times_agency = self.sql_handler.get_times_for_agency(non_null_column="eta_berth")
+
         counts = self.sql_handler.count_synchronous_shipcall_times(query_time, all_df_times=all_times_agency)
         violation_state = counts > maximum_threshold
 
@@ -952,6 +955,9 @@ class ValidationRuleFunctions(ValidationRuleBaseFunctions):
         times_agency = df_times.loc[df_times["participant_type"]==ParticipantType.AGENCY.value]
         query_time = times_agency.iloc[0].etd_berth
 
+        if all_times_agency is None:
+            all_times_agency = self.sql_handler.get_times_for_agency(non_null_column="etd_berth")
+
         # count the number of times, where a times entry is very close to the query time (uses an internal threshold, such as 15 minutes)
         counts = self.sql_handler.count_synchronous_shipcall_times(query_time, all_df_times=all_times_agency)
         violation_state = counts > maximum_threshold