"No one knows about that day or hour, not even the angels in heaven, nor the Son, but only the Father."
The Bible couldn't be clearer, right there in the Book of Matthew: chapter 24, verse 36.
But doomsayers have sworn since at least Roman times that they're better sourced than the angels themselves, boldly trotting out predictions for when the world will end as we know it; and when Christians, for example, believe Jesus will descend to earth and set off a chain of events resulting in the end of the world and a new heaven.
If the ancient Mayan calendar is no better at portending doomsday down to the hour (modern-day Maya don't even believe it themselves), then Dec. 21 is destined to join this random list of predictions mankind has survived so far.
May 21, 2011
May 21, 2011, was this decade's early attempt to get a jump on Judgment Day, courtesy of Oakland, Calif.-based Family Radio, a nonprofit evangelical Christian group. So convinced were many believers that some of them sold their worldly possessions.
Sept. 6, 1994
Let's continue with Family Radio, whose president, Harold Camping, had predicted the End of Days before: Sept. 6, 1994. Camping had been "thrown off a correct calculation because of some verses in Matthew 24," a company spokesman told ABC News just before May 21, 2011.
The Christian radio broadcaster had grown more confident by then, spending big bucks on 5,000 billboards, posters, fliers and digital bus displays across the country. He has since retired from the prophesy business.
June 12, 2008
Self-proclaimed prophet Yisrayl "Buffalo Bill" Hawkins convinced hundreds of his followers that nuclear war would begin June 12, 2008, if not sooner. It didn't, even after some members were apparently forced to buy doomsday food and supplies from Life Nutrition Products, a company owned by Hawkins, the founder of a religious sect in Abilene, Texas.
"Everything that he preaches has to do with people buying something," former House of Yahweh elder David Als of New York City told ABC News in a 2008 interview.
Edgar Whisenant didn't get it right the first time, either, when he predicted a mid-September 1988 Rapture, even publishing the books "88 Reasons Why the Rapture Will Be in 1988" and "On Borrowed Time." No Apocalypse, no problem. The former NASA engineer simply pushed his predictions off to three subsequent years and wrote books along the way, none of which reportedly sold as well as the first two.
He died in 2001.
Sometime in 1914
Jehovah's Witnesses first anticipated the end of times in 1914, noting decades later on their official website that "not all that was expected to happen in 1914 did happen, but it did mark the end of the Gentile Times and was a year of special significance."
March 21, 1843, to March 21, 1844
In the century before, renowned New England Baptist minister William Miller triggered what ultimately became known as the "great disappointment" after his failed prophesies that Christ would return sometime between March 21, 1843, and March 21, 1844, and then on Oct. 22, 1844.
June 9, 1994
More recently, Pastor John Hinkle of Christ Church Los Angeles told a Trinity Broadcasting Network audience that the "most cataclysmic experience that the world has ever known since the Resurrection ... is going to happen," according to the Christian Research Institute, which is home to "Bible Answer Man."
Hinkle said God, "in the most awesome voice," told him that "on Thursday, June the ninth , I will rip the evil out of this world."
The world might have missed it, however, because the prophesy came to pass invisibly, he said, according to the Christian Research Institute.
Sometime Before 1981
Chuck Smith, the prolific author and senior pastor of Calvary Chapel Costa Mesa in California, turned to scripture and simple math to prepare his flock for the Tribulation. "If I understand Scripture correctly, Jesus taught us that the generation which sees he 'budding of the fig tree,' the birth of the nation Israel, will be the generation that see the Lords return," he wrote in his book "End Times" (1978). "I believe that the generation 1948 is the last generation. Since a generation of judgment is forty years and the Tribulation period lasts seven years, I believe the Lord could come back for His Church any time before the Tribulation starts, which would mean any time before 1981. (1948+40-7=1981)."
"I could be wrong," he wrote in "Future Survival" (1978), "but it's a deep conviction in my heart, and all my plans are predicated upon that belief."
Smith was wrong and has not only abandoned his prophesying ways but since has looked askance at others who have gone down that road.
"The Jehovah's Witnesses, for example, thought the world was sure to end in 1914," Smith wrote in his book "Dateline Earth: Countdown to Eternity" (1989). "When it didn't happen, they merely moved the date up a few years."
The Year 2000
The prophetic-sounding year 2000 inspired too many doomsday predictions to list here. Suffice it to say that, in hindsight, there was really no need to party like it was 1999.