I can answer your question gabelogan. Working up front, I get alot of admission questions,(why I don't know, I'm just security) and I was asked the same thing. I didn't know the answer, so I asked an admissions supervisor that night, and he told me that they are starting to use a "P1V2". What it is, is you Pay once and can Visit twice. The days do not have to be consecutive, just twice during the season. So the admission you bought could be one or the other,
"so you might want to check with admissions or guest relations located up front, past the yellow booths, under the Nights of Fire sign."
see what i mean?