On the page where you put in the time/date/number of people etc it has some instructions at the top. In there is a link that says retrieve reservation. Once you put that in it will show you how many days you are staying and where.
eta: Now that I can get back into the system here is exactly what it says:
Update Your Profile
Are you an Annual Passholder and/or Florida Resident? If so, please add this information to your account profile so we can tailor your dining search.
.Retrieve Your Resort Reservation
Do you have a Resort reservation for the same days for which you're making dining reservations?
If so, please retrieve your reservation.
The words retrieve your reservation is a link.