INVENTORY MONTHEND CLOSING

Please can you tell me if there are any implications of setting up Inventory close periods to stop inventory transactions affecting previous month, during a financial year, or do I have to wait until end of the financial year.

If the answer is positive, do I have to setup all the months then close each one in turn until I get to the current month or can I setup a combined month period (e.g. Aug - Dec), then setup Jan, Feb etc.