create table t ( test1 varchar2(22) )Table created.
insert into t values ( '07/23/2001 02:20:55 AM' )1 row(s) inserted.
select to_char(test1, 'hh:mi:ss') 
     from tORA-01722: invalid numberMore Details: https://docs.oracle.com/error-help/db/ora-01722