Merge branch 'main' into html-repr-style-dropdowns

pydata · dcherian · May 30, 2025 · May 26, 2025 · May 28, 2025 · May 28, 2025
commit 88e950bcc5393139a083db81809246ca1618ad6f
diff --git a/doc/whats-new.rst b/doc/whats-new.rst
@@ -54,6 +54,21 @@ Bug fixes
   dropdown sections).
   (:pull:`10353`, :pull:`10354`)
   By `Benoit Bovy <https://github.com/benbovy>`_.
+- Raise an error when attempting to encode :py:class:`numpy.datetime64` values
+  prior to the Gregorian calendar reform date of 1582-10-15 with a
+  ``"standard"`` or ``"gregorian"`` calendar. Previously we would warn and
+  encode these as :py:class:`cftime.DatetimeGregorian` objects, but it is not
+  clear that this is the user's intent, since this implicitly converts the
+  calendar of the datetimes from ``"proleptic_gregorian"`` to ``"gregorian"``
+  and prevents round-tripping them as :py:class:`numpy.datetime64` values
+  (:pull:`10352`). By `Spencer Clark <https://github.com/spencerkclark>`_.
+
+Performance
+~~~~~~~~~~~
+- Lazily indexed arrays now use less memory to store keys by avoiding copies
+  in :py:class:`~xarray.indexing.VectorizedIndexer` and :py:class:`~xarray.indexing.OuterIndexer`
+  (:issue:`10316`).
+  By `Jesse Rusak <https://github.com/jder>`_.
 
 Documentation
 ~~~~~~~~~~~~~