BUG: fix to_datetime with np.datetime64[ps] giving wrong conversion (#60342)

Author: yuanx749

doc/source/whatsnew/v3.0.0.rst

@@ -626,6 +626,7 @@ Datetimelike
 - Bug in :meth:`Series.dt.microsecond` producing incorrect results for pyarrow backed :class:`Series`. (:issue:`59154`)
 - Bug in :meth:`to_datetime` not respecting dayfirst if an uncommon date string was passed. (:issue:`58859`)
 - Bug in :meth:`to_datetime` reports incorrect index in case of any failure scenario. (:issue:`58298`)
+- Bug in :meth:`to_datetime` wrongly converts when ``arg`` is a ``np.datetime64`` object with unit of ``ps``. (:issue:`60341`)
 - Bug in setting scalar values with mismatched resolution into arrays with non-nanosecond ``datetime64``, ``timedelta64`` or :class:`DatetimeTZDtype` incorrectly truncating those scalars (:issue:`56410`)
 
 Timedelta

pandas/_libs/src/vendored/numpy/datetime/np_datetime.c

@@ -660,11 +660,12 @@ void pandas_datetime_to_datetimestruct(npy_datetime dt, NPY_DATETIMEUNIT base,
     perday = 24LL * 60 * 60 * 1000 * 1000 * 1000 * 1000;
 
     set_datetimestruct_days(extract_unit(&dt, perday), out);
-    out->hour = (npy_int32)extract_unit(&dt, 1000LL * 1000 * 1000 * 60 * 60);
-    out->min = (npy_int32)extract_unit(&dt, 1000LL * 1000 * 1000 * 60);
-    out->sec = (npy_int32)extract_unit(&dt, 1000LL * 1000 * 1000);
-    out->us = (npy_int32)extract_unit(&dt, 1000LL);
-    out->ps = (npy_int32)(dt * 1000);
+    out->hour =
+        (npy_int32)extract_unit(&dt, 1000LL * 1000 * 1000 * 1000 * 60 * 60);
+    out->min = (npy_int32)extract_unit(&dt, 1000LL * 1000 * 1000 * 1000 * 60);
+    out->sec = (npy_int32)extract_unit(&dt, 1000LL * 1000 * 1000 * 1000);
+    out->us = (npy_int32)extract_unit(&dt, 1000LL * 1000);
+    out->ps = (npy_int32)(dt);
     break;
 
   case NPY_FR_fs:

pandas/tests/tools/test_to_datetime.py

@@ -3668,3 +3668,12 @@ def test_to_datetime_mixed_awareness_mixed_types(aware_val, naive_val, naive_fir
                 to_datetime(vec, format="mixed")
             with pytest.raises(ValueError, match=msg):
                 DatetimeIndex(vec)
+
+
+def test_to_datetime_wrapped_datetime64_ps():
+    # GH#60341
+    result = to_datetime([np.datetime64(1901901901901, "ps")])
+    expected = DatetimeIndex(
+        ["1970-01-01 00:00:01.901901901"], dtype="datetime64[ns]", freq=None
+    )
+    tm.assert_index_equal(result, expected)