Good question - there has been some debate about that in similar threads, yet I haven't seen a definitive answer. Some want to say it's 10-8, though there's no Disney source - logic behind that one seems to be take the latest used opening and the earliest used closing (without special events) and call these "regular" with everything else bring "added". Others seem to want to call it variable by season but whatever hours are first posted by Disney for a given month are "regular" with any eventual extensions being "added" or "bonus".[/QUOTE]
I actually like your answer, I think it's the closest. So my point is, if Disney posts June hours from 9-11, then your ticket you bought is for hours 9-11. If they add extra hours like they used to, that's just a bonus of hours, not because that's the way it was last year or that you're paying more for less hours. It may be less hours but just because they were open last year until 12am, doesn't mean they have to stay open this year until 12am unless it's posted as regular hours. Using Jimmy's math, everything is before 10am and after 8pm so that ticket is guaranteed hours between 10 and 8, anything before or after that is bonus hours no matter what the hours have been the last 10 years.