Dear Prasit
Let me brief what you need, and please point out the wrong ones.
1. The purpose to do Month-end on Aug. 8th is only to create some reports (AR, AP, GL and Inventory) dated on Aug. 8th for your New ERP as the initial data.
2. You still need a normal Month-end operation on Aug. 31st (08/01~08/31) as before!