What period should I use in Initial Mass Copy for Tax Book

 I am creating a new tax book in the middle of my fiscal year (October).  The last fiscal year ended 12/31/08 and I have been running depreciation in the corporate books each month since then.  Do I need to do an initial mass copy with the beginning period of December 2008 and then do periodic mass copies for each month after that?  I read in the Oracle documentation that you have to do an initial mass copy on a fiscal year that has been closed.