Asset Mass Changes of Dep. Method - Bonus Depreciation

Hello

My company wants to take advantage of the Bonus Depreciation by performing mass changes of assets via Mass change process.

I have applied patch 6511705:R12.FA.B which Creates additional 50% and 30% seeded bonus depreciation methods in Oracle.

I have demoed the mass change process to the end users and they seem ok with the functional steps. They want to update assets that belong to AMT and Federal books, no updates to corporate nor state books.

Functional org presents the following questions:

1) What is the best time in a given period to perform the mass changes? please see attached month end process document that  accountants use on tax books at time of closing.