The Oracle dbms_job.submit procedure accepts three parameters, the
name of the job to submit, the start time for the job, and the interval
to execute the job:
dbms_job.submit(
what=>'statspack_alert.sql;',
next_date=>sysdate+1/24, -- start next hour
interval=>'sysdate+1/24'); --
Run every hour

--
--------------------------------------------------------------------------
-- Using
dbms_job.submit to submit job to begin at 0600 and run every
hour
--
--------------------------------------------------------------------------
dbms_job.submit(

--
-----------------------------------------------------------------------------
-- Using
dbms_job.submit to submit job to begin at 0900 and run 12
hours later
--
-----------------------------------------------------------------------------
dbms_job.submit(

--
---------------------------------------------------------------------------------
-- Using
dbms_job.submit to submit job to begin at 0600 and run every
10 minutes
--
---------------------------------------------------------------------------------
dbms_job.submit(

--
---------------------------------------------------------------------------------------------
-- Using
dbms_job.submit to submit job to begin at 0600 and run every
hour, Monday - Friday
--
---------------------------------------------------------------------------------------------
dbms_job.submit(

Related dbms_job articles:
Advanced job scheduling with dbms_job
Oracle
dbms_job example
DBMS_JOB package tips