diff --git a/xarray/core/types.py b/xarray/core/types.py
index a5978405db4..97dcf9e1065 100644
--- a/xarray/core/types.py
+++ b/xarray/core/types.py
@@ -88,14 +88,15 @@
 else:
     DTypeLikeSave: Any = None
 
-DatetimeLikeNoCFTime = Union[pd.Timestamp, datetime.datetime, np.datetime64]
+# https://mypy.readthedocs.io/en/stable/common_issues.html#variables-vs-type-aliases
 try:
     from cftime import datetime as CFTimeDatetime
-
-    DatetimeLike = Union[DatetimeLikeNoCFTime, CFTimeDatetime]
 except ImportError:
-    CFTimeDatetime = Any
-    DatetimeLike = DatetimeLikeNoCFTime
+    CFTimeDatetime = np.datetime64
+
+DatetimeLike: TypeAlias = (
+    pd.Timestamp | datetime.datetime | np.datetime64 | CFTimeDatetime
+)
 
 
 class Alignable(Protocol):