-- https://docs.oracle.com/en/database/oracle/oracle-database/23/sqlrf/CAST.html
SELECT CAST('1999-12-01 11:00:00 -8:00'
       AS TIMESTAMP WITH TIME ZONE
       DEFAULT '2000-01-01 01:00:00 -8:00' ON CONVERSION ERROR,
       'YYYY-MM-DD HH:MI:SS TZH:TZM',
       'NLS_DATE_LANGUAGE = American')
  FROM DUAL;