The October date (when the earthquakes are supposed to end) is probably a temporary thing to fall back on, at least.
The October date is the end of the world. You see, May 21st is when Jesus is coming back for the rapture and then we are facing 5 months of judgment that will be terrible. There is no salvation after May 21st and by October 21st, the world will be destroyed. So if Camping is still here on May 22nd, he himself will be facing judgment.