<code>
CREATE OR REPLACE TRIGGER trg_lock_bonus
 BEFORE
  INSERT OR DELETE OR UPDATE
 ON bonus
REFERENCING NEW AS NEW OLD AS OLD
declare
  e_lock_bonus exception;

  pragma exception_init
    (e_lock_bonus, -20001);

begin
  if (to_char(sysdate, 'hh24mi') between '1300' and '1400') then
     raise_application_error(-20001,
     'kein Dateienverkehr zwischen 13 und 14h');
  end if;
end;
/
</code>