May 21, 2011, and Other 'Judgment Days' That Have Come and Gone

May 11, 2011— -- 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 down to the day for the Final Judgment, when, Christians believe, Jesus will descend to earth and set off a chain of events resulting in the end of the world and a new heaven.

May 21, 2011, is the latest attempt to get a jump on Judgment Day, courtesy of Oakland, Calif.-based Family Radio, a nonprofit evangelical Christian group. And, assuming we're all here to follow up, it will make a nice addition on May 22 to this random list of predicted Second Comings we've survived so far.

1. Let's start with Family Radio, whose president, Harold Camping, 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 this month.

The Christian radio broadcaster is apparently more confident this time around, spending big bucks on 5,000 billboards, posters, fliers and digital bus displays across the country.

2. 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. We're unable to confirm where he's awaiting the big day.