Oracle Scheduler - Oracle 10g/11g Data and Database Management Utilities - page 212

Intersect scenario
In this intersect scenario only the dates that are both a Sunday and the first day of the
month will be displayed.

This schedule selects every Sunday:

BEGIN
sys.dbms_scheduler.create_schedule(
repeat_interval => 'FREQ=WEEKLY;BYDAY=SUN' ,
start_date => systimestamp at time zone 'America/Mexico_City',
comments => 'Every Sunday',
schedule_name => '"SYS"."EVERY_SUNDAY"');
END;
/

The next scenario intersects the resulting timestamps from EVERY_SUNDAY with the
first day of the month.

BEGIN
sys.dbms_scheduler.create_schedule(
repeat_interval => ' FREQ=MONTHLY;BYMONTHDAY=1;INTERSECT=EVERY_
SUNDAY ',
start_date => systimestamp at time zone 'America/Mexico_City',
comments => 'Every Sunday 1st during the year',
schedule_name => '"SYS"."EVERY_SUNDAY_1ST"');
END;
/

Only the common dates are selected by this schedule.

COMBINED SCHEDULE - INTERSECT

EVERY_SUNDAY FIRST DAY OF THE MONTH

First day of
each month

Sundays

FREQ=MONTHLY;BYMONTHDAY=1;INTERSECT=EVERY_SUNDAY