That's a Scarefest date! One of the best times of year to visit the park - park is open 10am-9pm and there'll be mazes, roaming actors and (possibly) scare zones to enjoy as well as the rides. You may want to consider some fast tracks though if you've only got one day as it's a Saturday - we all visited as a group on the equivalent date last year and it was EXTREMELY busy. The first couple of hours (10-12) aren't too bad however, so that's the best time to do all the coasters before the crowds arrive.
Thanks for the tips, I'll be sure to consider the FastTrack although I might be going from the 19th of October until Halloween.