This is all out of my memory, so anyone jump in and correct me if I'm wrong!
Ok, for the excursions it's 60 days in advance for everyone.
Palo's is a different story. For just a regular cruiser, it's when you arrive on the ship. I believe it's different somehow if you're concierge level or on a package plan. You need to read your documentation if you're in either of those, it'll spell it out for you.