Oracle : Changing the Frequency of schedules in Oracle 10g

How to change the frequency of schedules in Oracle 10g
BEGIN
sys.DBMS_SCHEDULER.SET_ATTRIBUTE (
name => '"{OWNER}"."{SCHEDULE_NAME}"',
attribute => 'repeat_interval',
value => 'FREQ=WEEKLY;BYDAY=TUE,WED,THU,FRI,SAT;BYHOUR=10;BYMINUTE=30;BYSECOND=0');
END;/