If points issued August 2007, you can bank anytime on or before March 31, 2008. Use for trip anytime from August 1, 2008 to July 31, 2009.
As to those banked points and any issued August 1, 2008, you can call to reserve up to 11 months in advance at home resort. In other words, if you banked today, you could call today to reserve anytime between August 1, 2008 and February 5, 2009 using both those banked points and those to be issued August 1, 2008.
Always remember, you can always reserve 11 months in advance at home resort (7 at others). Points you use are determined by date you will be there not date you call.
If what you are talking about is to bank points you will get August 1, 2008, you will have until March 31, 2009 to bank and use those for trip between August 1, 2009 and July 31, 2010.