Here is the PL/SQL Snippet to create and schedule a batch job.
Note : Please test and modify accordingly as per your requirements.
BEGIN
DBMS_SCHEDULER.CREATE_JOB (
job_name => 'MY_BATCH_JOB',
job_type => 'PLSQL_BLOCK',
job_action => 'BEGIN MY_PACKAGE.MY_PROCEDURE; END;',
start_date => SYSTIMESTAMP,
enabled => TRUE
);
END;