If the 08 points were banked, then yes, they would be good from August 1st, 2009 through July 31st of 2010. If you want to go prior to August 1st, you could borrow 09 points into the 08 UY.
UY is when you get your points and the advice is to get one that falls just before you typically travel so that you have flexibility in banking the points if you have to cancel a trip or reuse them without restrictions. If you cancel a trip less than 31 days before check in, then the points go into a "holding" account and there are restrictions on what you can do with them.
Good luck!~