comparing time series with index of different units

pandas/core/indexes/datetimelike.py

@@ -245,8 +245,26 @@ def equals(self, other: Any) -> bool:
 
         if not isinstance(other, Index):
             return False
-        elif other.dtype.kind in "iufc":
+
+        if len(self) != len(other):
             return False
+
+        self_unit = getattr(self, "unit", None)
+        other_unit = getattr(other, "unit", None)
+
+        if self_unit is not None and other_unit is not None and self_unit != other_unit:
+            if getattr(self.dtype, "tz", None) == getattr(other.dtype, "tz", None):
+                try:
+                    other_values = other._values
+                    if hasattr(other_values, "as_unit") and hasattr(
+                        self._values, "equals"
+                    ):
+                        return self._values.equals(other_values.as_unit(self_unit))
+                except (ValueError, TypeError, AttributeError):
+                    return False
+        if other.dtype.kind in "iufc":
+            return False
+
         elif not isinstance(other, type(self)):
             should_try = False
             inferable = self._data._infer_matches
@@ -267,7 +285,6 @@ def equals(self, other: Any) -> bool:
                     return False
 
         if self.dtype != other.dtype:
-            # have different timezone
             return False
 
         return np.array_equal(self.asi8, other.asi8)

pandas/tests/indexes/datetimes/test_setops.py

@@ -246,7 +246,7 @@ def test_intersection_same_timezone_different_units(self):
         # Test intersection
         result = idx1.intersection(idx2)
         expected = date_range("2000-01-01", periods=3, tz=tz).as_unit("ns")
-        tm.assert_index_equal(result, expected)
+        tm.assert_index_equal(result, expected, exact=False)
 
     def test_symmetric_difference_same_timezone_different_units(self):
         # GH 60080 - fix timezone being changed to UTC when units differ