This should work ...
Code:
VARIABLE jobno number;

Begin
  DBMS_Job.Submit
     (
     job => :jobno,
     what => 'reset_nbr;',
     next => Trunc(SysDate,'MM')+(2/24),
     interval => 'Trunc(SysDate,'MM')+(2/24)'
     );
End;
/
Commit;