SNOW-1730297: update docstring for to_pandas and write_pandas behavior (

#2456)

src/snowflake/snowpark/dataframe.py

@@ -802,6 +802,11 @@ def to_pandas(
 
             2. If you use :func:`Session.sql` with this method, the input query of
             :func:`Session.sql` can only be a SELECT statement.
+
+            3. For TIMESTAMP columns:
+            - TIMESTAMP_LTZ and TIMESTAMP_TZ are both converted to `datetime64[ns, tz]` in pandas,
+            as pandas cannot distinguish between the two.
+            - TIMESTAMP_NTZ is converted to `datetime64[ns]` (without timezone).
         """
         with open_telemetry_context_manager(self.to_pandas, self):
             result = self._session._conn.execute(

src/snowflake/snowpark/session.py

@@ -2628,16 +2628,20 @@ def write_pandas(
             0   1  Jane
 
         Note:
-            Unless ``auto_create_table`` is ``True``, you must first create a table in
+            1. Unless ``auto_create_table`` is ``True``, you must first create a table in
             Snowflake that the passed in pandas DataFrame can be written to. If
             your pandas DataFrame cannot be written to the specified table, an
             exception will be raised.
 
-            If the dataframe is Snowpark pandas :class:`~modin.pandas.DataFrame`
+            2. If the dataframe is Snowpark pandas :class:`~modin.pandas.DataFrame`
             or :class:`~modin.pandas.Series`, it will call
             :func:`modin.pandas.DataFrame.to_snowflake <modin.pandas.DataFrame.to_snowflake>`
             or :func:`modin.pandas.Series.to_snowflake <modin.pandas.Series.to_snowflake>`
             internally to write a Snowpark pandas DataFrame into a Snowflake table.
+
+            3. If the input pandas DataFrame has `datetime64[ns, tz]` columns and `auto_create_table` is set to `True`,
+            they will be converted to `TIMESTAMP_LTZ` in the output Snowflake table by default.
+            If `TIMESTAMP_TZ` is needed for those columns instead, please manually create the table before loading data.
         """
         if isinstance(self._conn, MockServerConnection):
             self._conn.log_not_supported_error(