BUG: ensure_datetime64ns with bigendian array (#30976)

doc/source/whatsnew/v1.1.0.rst

@@ -82,7 +82,7 @@ Numeric
 
 Conversion
 ^^^^^^^^^^
-
+- Bug in :class:`Series` construction from NumPy array with big-endian ``datetime64`` dtype (:issue:`29684`)
 -
 -
 

pandas/_libs/tslibs/conversion.pyx

@@ -99,6 +99,11 @@ def ensure_datetime64ns(arr: ndarray, copy: bool=True):
 
  shape = (<object>arr).shape
 
+ if (<object>arr).dtype.byteorder == ">":
+ # GH#29684 we incorrectly get OutOfBoundsDatetime if we dont swap
+ dtype = arr.dtype
+ arr = arr.astype(dtype.newbyteorder("<"))
+
  ivalues = arr.view(np.int64).ravel()
 
  result = np.empty(shape, dtype=NS_DTYPE)

pandas/tests/series/test_constructors.py

@@ -967,6 +967,15 @@ def test_constructor_with_naive_string_and_datetimetz_dtype(self, arg):
  expected = Series(pd.Timestamp(arg)).dt.tz_localize("CET")
  tm.assert_series_equal(result, expected)
 
+ def test_constructor_datetime64_bigendian(self):
+ # GH#30976
+ ms = np.datetime64(1, "ms")
+ arr = np.array([np.datetime64(1, "ms")], dtype=">M8[ms]")
+
+ result = Series(arr)
+ expected = Series([Timestamp(ms)])
+ tm.assert_series_equal(result, expected)
+
  @pytest.mark.parametrize("interval_constructor", [IntervalIndex, IntervalArray])
  def test_construction_interval(self, interval_constructor):
  # construction from interval & array of intervals

pandas/tests/tslibs/test_conversion.py

@@ -72,6 +72,15 @@ def test_length_zero_copy(dtype, copy):
  assert result.base is (None if copy else arr)
 
 
+def test_ensure_datetime64ns_bigendian():
+ # GH#29684
+ arr = np.array([np.datetime64(1, "ms")], dtype=">M8[ms]")
+ result = conversion.ensure_datetime64ns(arr)
+
+ expected = np.array([np.datetime64(1, "ms")], dtype="M8[ns]")
+ tm.assert_numpy_array_equal(result, expected)
+
+
 class SubDatetime(datetime):
  pass