I'm kind of confused about how to purchase the one day photopass for Shanghai. I wanted to purchase ahead of time, but not sure if you have to wait and purchase it once you are in the park?? If you purchase ahead of time, how does it know what day it is for as it appears there is not a place when ordering in the photo app to specify that? I just don't want to buy it now and then have it be expired when I get there because it was only good on date of purchase or something??? Thanks for clarification!!