This forum is to discuss different features/issues of Oracle Financials modules ( GL - General Ledger, AP - Accounts Payable, AR - Accounts Receivable, FA - Fixed Assets & CM - Cash Management ).
Please check if you have assigned the GL ledger option and MO: operating unit to your payable responsibility. I think this could one possible reason why you are not able to see the periods.
Also check your payable option and finance options are properly defined and saved.