Cindybell,
I think the three day tickets never expire if you have extra days? The five day is five consecutive days, then it's done.
I got the five day passes just to get tickets in the mail ahead of time, for using one day, both parks. It was only five bucks more than waiting in line at the gate for those two-park, one day tickets that you cannot get in advance.
However, now I wish I'd gotten two day tickets for just another five bucks, so that I'd have days left for my next trip, in a couple of years.
Obviously, we are mainly doing Disney this go-round.
JenniferK