Husband might join us for a couple days - ticket question

So it looks like my husband might be able to get away from work and join us for a few days in the middle of our upcoming trip. Ideally I would get him a 2-day ticket but there are only 2 days with park availability so it won’t let me. I can buy a 1-day ticket though. (Note: this is annoying, if I have a 2-day ticket and can make 2 park reservations then…why not). I want to buy his park ticket tonight and secure a park reservation for the one day. IF it ends up that he can’t come, we can still apply the value of the unused “expired” ticket to a future ticket right? And just to verify, if we wanted to purchase like a 5-day ticket in the future instead of the 1-day, we could still apply the value to that? I’m not worried about spending the money today, but a 1-day ticket price is painful and I don’t want to be totally out $200 if he’s not able to get away from work.

Yes you can always either change the date before the ticket expires, or use the value towards another ticket.