The US evangelical Christian broadcaster predicting that Judgment Day - or the 'Rapture' - will come tomorrow says he expects to stay close to a television or radio to monitor the unfolding apocalypse.
Harold Camping (89), previously made a failed prediction that Jesus Christ would return to Earth in 1994.
The head of the Christian radio network Family Stations Inc says that he is sure an earthquake will shake the Earth on May 21st, sweeping true believers to heaven and leaving others behind to be engulfed in the world's destruction over a few months. "We know without any shadow of a doubt it is going to happen," Mr Camping said.
His Family Radio has 66 US stations and broadcasts in more than 30 languages through international affiliates.
His supporters have posted about 2,200 billboards around the United States about the coming apocalypse, and dozens of followers have driven across the country to spread the news.
The Rapture - the belief that Christ will bring the faithful into paradise prior to a period of tribulation on Earth that precedes the end of time - is a relatively new notion compared to Christianity itself, and most Christians don't
believe in it. Even believers rarely attempt to set a date for the event.
Mr Camping, a civil engineer who once ran his own construction business, plans to spend May 21st with his wife in Alameda, in northern California, and watch the doomsday unfold.
"I'll probably try to be very near a TV or a radio or something," he said. "I'll be interested in what's happening on the other side of the world as this begins."
Like his last prediction, Mr Camping's doomsday date is based on his reading of the Bible and a timeline dating back to ancient events including the Biblical flood survived by Noah.
Mr Camping's pronouncement of a specific date for the apocalypse puts him outside the Christian mainstream.
Jerry Jenkins, co-author with Tim LaHaye of the Left Behind series of apocalyptic novels that have sold millions of copies worldwide, has a problem with the prediction.
"As a believer, I'm already a kook compared to most people, so for someone to choose a date and get everyone excited about a certain time, my problem is it makes us look worse," said Mr Jenkins (61).
Stephen O'Leary, an expert in religious communication at the University of Southern California, said the idea of rapture espoused by Mr Camping and some more mainstream Christians first appeared in Christian teaching in the 19th century.
"It is very appealing to people," said Barbara Rossing, professor of the New Testament at the Lutheran School of Theology at Chicago who describes a huge apocalyptic "prophecy industry" including video games, board games and books.
Atheists are reacting to Mr Camping's pronouncement in their own way.
In Tacoma, Washington, atheists have organised a party for tomorrow night at an arcade, under the banner "countdown to backpedalling", on the assumption that Mr Camping and Family Radio will change their story if Judgment Day does not come.
At least 100 people are expected at the party, said Sam Mulvey (33), an organiser of the event and the producer of a weekly atheist radio show in Tacoma.
"If the world still exists the next day, Family Radio is going to have to say something and most of the time they backpedal, and that's what we're counting down to," he said.