diff --git a/tests/test_timeseries_benchmark.py b/tests/test_timeseries_benchmark.py
index 704f506..28a6137 100644
--- a/tests/test_timeseries_benchmark.py
+++ b/tests/test_timeseries_benchmark.py
@@ -39,7 +39,7 @@ class ConceptConfig:
         concept_id="C2036881735-POCLOUD",
         resolution_meters=28000,
         backend="xarray",
-        start_datetime=datetime(2010, 1, 1),
+        start_datetime=datetime(2010, 1, 1, hour=0, minute=0, second=1),
         step="P1D",
         temporal_mode=TemporalMode.point,
         zarr_params=ZarrParams(variable="analysed_sst"),
@@ -48,7 +48,7 @@ class ConceptConfig:
         concept_id="C1996881146-POCLOUD",
         resolution_meters=1000,
         backend="xarray",
-        start_datetime=datetime(2010, 1, 1),
+        start_datetime=datetime(2010, 1, 1, hour=0, minute=0, second=1),
         step="P1D",
         temporal_mode=TemporalMode.point,
         zarr_params=ZarrParams(variable="analysed_sst"),