Oracle Scheduled Jobs

TO CREATE A JOB:

Begin

 Dbms_scheduler.Create_job (

    Job_name => 'RUN_JOB_TO_RUN',

    Job_type => 'PLSQL_BLOCK',

    Job_action => 'BEGIN JOB_TO_RUN(); END;',

    Start_date => To_timestamp_tz('10-NOV-2015 13:00:00','DD-MM-YYYY HH24:MI:SS'),

    Repeat_interval => 'FREQ = DAILY; BYHOUR=13',

    comments => 'Some job to run.',

    Enabled => True);

End;

TO UPDATE A JOB:

begin

Dbms_scheduler.Set_attribute

(  name => 'RUN_JOB_TO_RUN'

,   Attribute =>'REPEAT_INTERVAL'

,   value =>'FREQ=DAILY; BYHOUR=2');

End;