diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 0aed08d46657e..b0f9f8ac8b2fd 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -4047,9 +4047,10 @@ def _to_safe_for_reshape(self):
         """
         return self
 
-    def _convert_for_op(self, value):
+    def _validate_fill_value(self, value):
         """
-        Convert value to be insertable to ndarray.
+        Check if the value can be inserted into our array, and convert
+        it to an appropriate native type if necessary.
         """
         return value
 
@@ -4228,7 +4229,8 @@ def putmask(self, mask, value):
         """
         values = self.values.copy()
         try:
-            np.putmask(values, mask, self._convert_for_op(value))
+            converted = self._validate_fill_value(value)
+            np.putmask(values, mask, converted)
             if is_period_dtype(self.dtype):
                 # .values cast to object, so we need to cast back
                 values = type(self)(values)._data
diff --git a/pandas/core/indexes/datetimes.py b/pandas/core/indexes/datetimes.py
index f269495f6011a..2d166773dda2c 100644
--- a/pandas/core/indexes/datetimes.py
+++ b/pandas/core/indexes/datetimes.py
@@ -325,13 +325,11 @@ def __reduce__(self):
         d.update(self._get_attributes_dict())
         return _new_DatetimeIndex, (type(self), d), None
 
-    def _convert_for_op(self, value):
+    def _validate_fill_value(self, value):
         """
         Convert value to be insertable to ndarray.
         """
-        if self._has_same_tz(value):
-            return Timestamp(value).asm8
-        raise ValueError("Passed item and index have different timezone")
+        return self._data._validate_setitem_value(value)
 
     def _is_comparable_dtype(self, dtype: DtypeObj) -> bool:
         """
diff --git a/pandas/core/indexes/numeric.py b/pandas/core/indexes/numeric.py
index e8b7efeee8852..f6859cbc4c0a2 100644
--- a/pandas/core/indexes/numeric.py
+++ b/pandas/core/indexes/numeric.py
@@ -116,7 +116,7 @@ def _shallow_copy(self, values=None, name: Label = lib.no_default):
             return Float64Index._simple_new(values, name=name)
         return super()._shallow_copy(values=values, name=name)
 
-    def _convert_for_op(self, value):
+    def _validate_fill_value(self, value):
         """
         Convert value to be insertable to ndarray.
         """