Mid Month Upgrade R11 to R12

 Would like to know if you can upgrade mid month from R11 to R12, ensuring that all the accounting is completed and in GL and all the interfaces have been completed.

In short,  although the last period has been closed properly, the current period has some transactions fully accounted and transferred to GL, all the Sub-Ledgers for the currrent month are open and the current months close will be conducted on R12 after further transaction in R12 for the period ( so there will be some transaction for the current period in R11 and then more transaction created in R12 once the upgrade has been done).