Handle nonexistent end dates for resampling

Author: rob-sil

doc/source/whatsnew/v3.0.0.rst

@@ -615,6 +615,7 @@ Groupby/resample/rolling
 - Bug in :meth:`DataFrameGroupBy.cumsum` where it did not return the correct dtype when the label contained ``None``. (:issue:`58811`)
 - Bug in :meth:`DataFrameGroupby.transform` and :meth:`SeriesGroupby.transform` with a reducer and ``observed=False`` that coerces dtype to float when there are unobserved categories. (:issue:`55326`)
 - Bug in :meth:`Rolling.apply` where the applied function could be called on fewer than ``min_period`` periods if ``method="table"``. (:issue:`58868`)
+- Bug in :meth:`Series.resample` could raise when the the date range ended shortly before DST. (:issue:`58380`)
 
 Reshaping
 ^^^^^^^^^

pandas/core/resample.py

@@ -2466,7 +2466,7 @@ def _get_timestamp_range_edges(
         )
         if isinstance(freq, Day):
             first = first.tz_localize(index_tz)
-            last = last.tz_localize(index_tz)
+            last = last.tz_localize(index_tz, nonexistent="shift_forward")
     else:
         first = first.normalize()
         last = last.normalize()

pandas/tests/resample/test_datetime_index.py

@@ -958,6 +958,20 @@ def _create_series(values, timestamps, freq="D"):
     tm.assert_series_equal(result, expected)
 
 
+def test_resample_dst_midnight_last_nonexistent():
+    # GH 58380
+    ts = Series(
+        1,
+        date_range("2024-04-19", "2024-04-20", tz="Africa/Cairo", freq="15min"),
+    )
+
+    expected = Series([len(ts)], index=DatetimeIndex([ts.index[0]], freq="7D"))
+
+    result = ts.resample("7D").sum()
+    print(f"{result=}")
+    tm.assert_series_equal(result, expected)
+
+
 def test_resample_daily_anchored(unit):
     rng = date_range("1/1/2000 0:00:00", periods=10000, freq="min").as_unit(unit)
     ts = Series(np.random.default_rng(2).standard_normal(len(rng)), index=rng)