Set A Job To Run Every Hour on Top of The Hour

In sql*plus:
VARIABLE jobno number;
BEGIN
DBMS_JOB.SUBMIT(:jobno,’myuser.myproc();',TRUNC(SYSDATE+(1/24), 'HH'),
'TRUNC(SYSDATE+(1/24),''HH'')');
END;

PRINT jobno; -- to display assigned job id to task