From 9b65f18f1029cbc4560ab0224a5e73099e085cf9 Mon Sep 17 00:00:00 2001
From: Patrick Hoefler <patrick_hoefler@gmx.net>
Date: Sat, 1 Nov 2025 22:55:55 +0000
Subject: [PATCH] BUG: Series.resample failing for non-nanosecond unit that's
 out of bounds for nano reso

---
 doc/source/whatsnew/v3.0.0.rst               |  1 +
 pandas/_libs/tslibs/offsets.pyx              | 17 +++++++++++++----
 pandas/tests/resample/test_datetime_index.py | 11 +++++++++++
 3 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/doc/source/whatsnew/v3.0.0.rst b/doc/source/whatsnew/v3.0.0.rst
index 12f522301e121..1927f47382c02 100644
--- a/doc/source/whatsnew/v3.0.0.rst
+++ b/doc/source/whatsnew/v3.0.0.rst
@@ -1180,6 +1180,7 @@ Groupby/resample/rolling
 - Bug in :meth:`Rolling.apply` for ``method="table"`` where column order was not being respected due to the columns getting sorted by default. (:issue:`59666`)
 - 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 date range ended shortly before a non-existent time. (:issue:`58380`)
+- Bug in :meth:`Series.resample` raising error when resampling non-nanosecond resolutions out of bounds for nanosecond precision (:issue:`57427`)
 
 Reshaping
 ^^^^^^^^^
diff --git a/pandas/_libs/tslibs/offsets.pyx b/pandas/_libs/tslibs/offsets.pyx
index 8fb5e739d3a4e..be86118a2b9e2 100644
--- a/pandas/_libs/tslibs/offsets.pyx
+++ b/pandas/_libs/tslibs/offsets.pyx
@@ -5688,18 +5688,27 @@ def shift_month(stamp: datetime, months: int, day_opt: object = None) -> datetim
     cdef:
         int year, month, day
         int days_in_month, dy
+        npy_datetimestruct dts
+
+    if isinstance(stamp, _Timestamp):
+        creso = (<_Timestamp>stamp)._creso
+        val = (<_Timestamp>stamp)._value
+        pandas_datetime_to_datetimestruct(val, creso, &dts)
+    else:
+        # Plain datetime/date
+        pydate_to_dtstruct(stamp, &dts)
 
-    dy = (stamp.month + months) // 12
-    month = (stamp.month + months) % 12
+    dy = (dts.month + months) // 12
+    month = (dts.month + months) % 12
 
     if month == 0:
         month = 12
         dy -= 1
-    year = stamp.year + dy
+    year = dts.year + dy
 
     if day_opt is None:
         days_in_month = get_days_in_month(year, month)
-        day = min(stamp.day, days_in_month)
+        day = min(dts.day, days_in_month)
     elif day_opt == "start":
         day = 1
     elif day_opt == "end":
diff --git a/pandas/tests/resample/test_datetime_index.py b/pandas/tests/resample/test_datetime_index.py
index ab88d221864c0..3cd7f6c336956 100644
--- a/pandas/tests/resample/test_datetime_index.py
+++ b/pandas/tests/resample/test_datetime_index.py
@@ -2171,6 +2171,17 @@ def test_arrow_timestamp_resample_keep_index_name():
     tm.assert_series_equal(result, expected)
 
 
+def test_resample_unit_second_large_years():
+    # GH#57427
+    index = DatetimeIndex(
+        date_range(start=Timestamp("1950-01-01"), periods=10, freq="1000YS", unit="s")
+    )
+    ser = Series(1, index=index)
+    result = ser.resample("2000YS").sum()
+    expected = Series(2, index=index[::2])
+    tm.assert_series_equal(result, expected)
+
+
 @pytest.mark.parametrize("freq", ["1A", "2A-MAR"])
 def test_resample_A_raises(freq):
     msg = f"Invalid frequency: {freq[1:]}"