Can we setup a 13 period fiscal year for 2010 only, using the same variant

Question

We currently have a fiscal year running from October. We have been taken over by a new comany who want our fiscal year to run from November. It has been decided that year 2010 will contain 13 periods.
Can someone help with how to set this up in OB29.
The current settings are for 12 normal periods and 4 special periods. Therefore it will not allow 13 periods to be setup in 2010. However, if I change the number of normal periods in the variant to 13 then there is a message saying that there are gaps in the other fiscal years which are not 2010.
What is the correct way to deal with the extra month? We are currently in 2010 which started in October and we don't want FY 2011 to start until November.
Thank you
Karen

Answer 1

Thank you for your reply, but the problem is that we want to add a 13th period.
The setup we have is as below.
1     29     4     0
2     26     5     0
3     26     6     0
4     30     7     0
5     28     8     0
6     25     9     0
7     30     10     0
8     27     11     0
9     30     12     0
10     29     13     0
11     27     1     +1
12     24     2     +1
12     31     3     +1
This is working fine to find October as period 13 when we use function DATE_TO_PERIOD_CONVERT, but there is an error in the setup saying 'Only define periods until 12'. When we try to run function LAST_DAY_IN_PERIOD_GET this crashes saying fiscal year variant not found for 2010.
There is a setting in the fiscal year variant which says
Calendar yr     2010  No.posting periods   12   No.special periods 4    
For 2010 only we want this to be 13 periods. Is this possible?
Thank you
Karen