diff --git a/src/xscen/utils.py b/src/xscen/utils.py
index 671dbeb2..08428cfd 100644
--- a/src/xscen/utils.py
+++ b/src/xscen/utils.py
@@ -346,6 +346,11 @@ def translate_time_chunk(chunks: dict, calendar: str, timesize: int) -> dict:
                     "all_leap": 366,
                     "366_day": 366,
                 }.get(calendar, 365.25)
+                if nt != int(nt):
+                    warnings.warn(
+                        f"The number of days in {chunks['time']} for calendar {calendar} is not an integer. "
+                        f"Chunks will not align perfectly with year ends."
+                    )
                 chunks[k] = int(nt)
             elif v == -1:
                 chunks[k] = timesize
diff --git a/tests/test_utils.py b/tests/test_utils.py
index b52e857a..00a09a8a 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -152,6 +152,12 @@ def test_ny(self, calendar):
         )
         assert out == {"time": ndays * 4, "lon": 50}
 
+    def test_warning(self):
+        with pytest.warns(UserWarning, match="The number of days"):
+            xs.utils.translate_time_chunk(
+                {"time": "3years", "lon": 50}, "standard", 3450
+            )
+
     def test_dict_of_dict(self):
         out = xs.utils.translate_time_chunk(
             {"tas": {"time": 10, "lon": 50}, "pr": {"time": -1, "lon": 50}},