Create RMA in previous date

 Hi,

I create a sales order and shipment on previous date.i.e 6june2012 and transaction is created on 6th june2012.But unfortunetly it was created by worngly.I need to reverse back all the information and financial impact on the same date i.e 6th june2012.

Is it possible to create RMA and receipt of goods in inventory and credit memo on the same date.i.e 6th june 2012?how inventory should be receipt in previous date?