Add subdaily check

pyrealm/pmodel/acclimation.py

@@ -222,6 +222,13 @@ def _validate_and_set_datetimes(self, datetimes: NDArray[np.datetime64]) -> None
         if spacing < 0:
             raise ValueError("Datetime sequence must be increasing")
 
+        # Validate that we are dealing indeed with subdaily data
+        if spacing > np.timedelta64(1, "D"):
+            raise ValueError(
+                "The AcclimationModel requires datetimes sampled at daily frequency "
+                "or faster."
+            )
+
         # Work out observations by date and look for incomplete dates at the start and
         # end of the time sequence
         dates = datetimes.astype("datetime64[D]")

pyrealm/pmodel/pmodel.py

@@ -715,7 +715,6 @@ def _fit_model(
             raise ValueError(
                 "The daily sampling window has not been set in the AcclimationModel"
             )
-
         # * Validate the previous realised values and standardise the internal
         #   representation as a dictionary.
         if previous_realised is None:

tests/unit/pmodel/test_acclimation_model.py

@@ -65,6 +65,20 @@
             ),
             id="Negative timedeltas",
         ),
+        pytest.param(
+            pytest.raises(ValueError),
+            "The AcclimationModel requires datetimes sampled at daily frequency "
+            "or faster.",
+            dict(
+                datetimes=np.arange(
+                    np.datetime64("2014-06-01 00:00"),
+                    np.datetime64("2014-07-01 00:00"),
+                    np.timedelta64(2, "D"),
+                    dtype="datetime64[s]",
+                )
+            ),
+            id="Not subdaily",
+        ),
         pytest.param(
             pytest.raises(ValueError),
             "Datetime spacing is not evenly divisible into a day",