Originally, Camping predicted that May 21 would be the "rapture" day, and that the remaining people who didn't get raptured would be subject to torment for exactly 5 months afterward (until October 21). October 21 was to be the "real" world end day according to him.
Now that jack crap has happened he says an "invisible" rapture took place and that now the world will still end on October 21...