wip

Author: MarcoGorelli

pandas/_libs/tslib.pyx

@@ -12,6 +12,7 @@ from cpython.object cimport PyObject
 import_datetime()
 
 
+import dateutil
 cimport numpy as cnp
 from numpy cimport (
     float64_t,
@@ -42,7 +43,6 @@ from pandas._libs.util cimport (
     is_float_object,
     is_integer_object,
 )
-import datetime as dt
 
 from pandas._libs.tslibs.np_datetime import OutOfBoundsDatetime
 from pandas._libs.tslibs.parsing import parse_datetime_string
@@ -723,12 +723,12 @@ cpdef array_to_datetime(
         if not is_same_offsets:
             _result = np.empty(n, dtype="object")
             for i in range(n):
-                if iresult[i] != iresult[i] or iresult[i] == NPY_NAT:
-                    _result[i] = result[i]
+                if iresult[i] == NPY_NAT:
+                    _result[i] = NaT
                     continue
-                _dt = dt.datetime.utcfromtimestamp(iresult[i]/1_000_000_000)
+                _dt = parse_datetime_string(str(result[i]))
                 if result_timezone[i] is not None:
-                    _tzinfo = pytz.FixedOffset(result_timezone[i]/60)
+                    _tzinfo = dateutil.tz.tzoffset(None, result_timezone[i])
                     _result[i] = _dt.replace(tzinfo=pytz.UTC).astimezone(_tzinfo)
                 else:
                     _result[i] = _dt

pandas/tests/tools/test_to_datetime.py

@@ -1353,11 +1353,11 @@ def test_mixed_offsets_with_native_datetime_raises(self):
         mixed = to_datetime(ser)
         expected = Series(
             [
-                "NaT",
+                NaT,
                 Timestamp("1990-01-01"),
                 Timestamp("2015-03-14T16:15:14.123-08:00").to_pydatetime(),
                 Timestamp("2019-03-04T21:56:32.620-07:00").to_pydatetime(),
-                None,
+                NaT,
             ],
             dtype=object,
         )