Hi, Jocelyn! Tickets for the Disney parks have had many names over the years - Super Passes, World Passports, and in the 90's there was a Length of Stay pass that allowed you to use the parks from the moment you checked in until midnight the day you checked out.
Today, Disney has "Magic Your Way" tickets where you create the exact ticket that fits your needs. If you go to the parks on your arrival day, even if it is in the evening, this will count as one of the park days you purchased on your ticket. The good part of this is you only pay for what you want, and also, to add on additional days gets cheaper with the more days you add. For example, to go from a 7 to an 8 day base ticket, it is only an additional $3 for that 8th day (prices are subject to change, sales tax is additional.) Click
HERE for a chart with ticket pricing.
Create the ticket that will offer your family the most magic for your vacation!