There's nowhere that you can see clearly how many days remain on a ticket. The way I have checked is to see how many days worth of fast passes it will allow me to reserve. For example, if there are only two days left on the tickets, it won't allow you to schedule a third day of FP+. Other option would be to call and provide the ticket number(s) and see if they can look it up for you. One of the flaws in
MDE in my opinion.