basis year business tax, WDA?

meibaker

1: in dec pass exam 2006, question:Calculate the assessable profits for the first three tax years, beginning 2004/05, clearly
showing all relevant dates. Also show the amount and dates of any overlap profits.
He commenced trading on 1 January 2005, and made his first accounts to 30 April 2006.
answers:
2004/05: 1 January 2005 – 5 April 2005
2005/06: 6 April 2005 – 5 April 2006
2006/07: 1 May 2005 – 30 April 2006
Overlap: 1 May 2005 – 5 April 2006
i am always have problem with the second basis year,
my calcultation for 2nd year is 1/5/05- 30/4/06, please someone explain this for me please
2: are all WRITE DOWN ALLOWANCE time apportioned??