Yep. That's how you can tell if a prophet is real. Edgar Cayce gave the date of 1998, Michael Scallion said 1998, I'm not sure of Nostridomus, but I believe he said 1988.
God gives man a chance to repent. There's an eb and flow to his prophacies. The world may turn to God one day, like right after 9/11, but within a month be back to their same 'ol selves. We always have a chance to hold off the end if man chooses to do so. If not, the end will come. That's why there's no Biblical date. God allows us time. Eventually, the angel will put one foot on the land, the other in the sea, and say "There will be no more delay."