I have 2 tickets with one day left. Can I add a day to these tickets? I may want to go to both parks and don't want to have to buy a 2 day ticket when I really only need one more day. Our grandson really wants to ride MIB, but we were only planning to go to IOA. So now I am thinking about getting them 2 day tickets, and using our extra day for US instead of Disney. If the crowds aren't bad we could also go to IOA and ride Spiderman again, (our favorite ride!). My husband and I were there in Sept. 2001 and were able to do both parks in one day, as there were no crowds at all. We did miss a few things at US but don't think there is enough there for a whole day, unless it is very crowded. We are going May 16 to May 23.