Must be in the hundreds. We only hear about the bigger ones, the 'prophesies' which become known on a world-wide scale. There are, of course, the many smaller religious groups who are always predicting the 'world will end on...."
You even see cartoons of such behaviour.
I have no doubt this question will bring forth the myriad 'bible bangers' who follow Hubpage Questions pertaining to Religion & Philosophy who will put forward their various quotations. Who is to say whether they're right or wrong. The date of Armageddon is always being shifted forward when the predicted one has arrived and nothing much has happened.