But religious scholars point out that while Camping and his group might be amusing -- even interesting -- their message has no factual basis. Thomas Groome, a professor of theology and religious education at Boston College, said Camping's math doesn't make sense.
"In the Gospel of Matthew, it says we know not the day or hour; only God knows the End time," he said. "Camping's calculations are totally contrived. He kind of says a thousand years must be equal to a day and multiply that by the number of floods. ... It's all so bizarre. If God doesn't tell the angels, he certainly doesn't tell Harold Camping."
Groome said Camping and his group are an example of "religion run amok" and lamented over "all the money wasted" on the billboards.
"The Bible isn't meant to be taken literally, "he said. "It is a book of faith, not a book of data that offers predictions. We will all still be here on May 22."