If the religious, who put their faith in God, and believe that every aspect of creation was planned with a purpose, according to Scripture, believers would follow their core logic that, so to, is the end of the world, thereby, defying predictability per mankind.
Scientists, who base their knowledge on what is proven upon sight, ie, seeing is believing, often struggle with the concept of a creator not seen with the naked eye. But, for all the scientific observations, research and innovative technology to aid their knowledge, they missed the recent, huge asteroid and even if it had been seen, could not have prevented or changed its course. A recent PBS episode of 'Nova' stated the real likelihood that the earth, as we know it, may well end, at any time, by the nuclear force and speed of an unseen asteroid that supercedes any bomb yet created by man.
The bottom line regarding the question "When will the world end" can only be answered with the fact that no human being knows. Whether it is destiny, a natural occurrence or at the hands of a madman with a nuclear bomb, we cannot predict the time and date of the end of the world.