Annual pass activation deadline?

[Hope Soda]

I am considering annual passes for our upcoming December trip (and several next year). However, there's a chance we will have to postpone the entire trip until February, or even April. If I buy annual passes in October or November, would I be able to activate them as late as April?

 

[randumb0]

If you only purchase the voucher and do not active it the expiration date is 2030.