I purchased a three day pass for the Duomo for 10 o'clock September 10. It turns out we cannot get there until afternoon. It is important for me to use elevator lift to the terraces. Since we cannot be at the gate at time on the ticket, will they allow us to use the pass later in the day for all including the elevator or must I buy new tickets? Thanks in advance for your help.

If it's a 3-day pass, couldn't you just go the following day?

Actually, reading the information on the Duomo site, I understand it to mean that you have a 3-day pass beginning at 10. It doesn't say anything about single visits to specific sites.

The terraces close at 18:30, (6:30 PM) and the latest you can enter them is at 18. Given time to wait for the elevator and ticket checking, I would want to be there no later than 17. Even that might give you only a brief glimpse.

We should be able to arrive by mid-afternoon on the 10th. Hopefully, we will be able to visit all. Thank you for your reply.