May 21, 2011 will mark the second coming of Christ, or at least that's what some Christian groups believe.

The date was calculated by Harold Camping, the leader of an independent Christian ministry called Family Radio Worldwide, which is based in Oakland, Calif. Camping's date is based on his interpretation of the Bible.

Camping's group isn't the only one following his apocalyptic prediction though. A number of loosely affiliated websites and radio broadcasts have created a movement independent of churches that have organized to proclaim the day as the end of the world.

Billboards, bus stop benches, and travelling caravans of RVs from Bridgeport, Conn. to Little Rock, Ark. are being used to spread the word, according to the AP. Allison Warden (pictured) has been helping to organize the campaign not only through billboards and post cards, but through the web, using her site We Can Know.

Camping, 89, says the Bible acts as a calendar by which the dates of prophecies can be calculated. "Beyond the shadow of a doubt, May 21 will be the date of the Rapture and the day of judgment," he told the AP.

While this isn't the first time that the end of the world has been predicted, there are many believers that will adhere to the date, even if it passes. "It would be like telling the Wright brothers that every other attempt to fly has failed, so you shouldn't even try," Chris McCann, who works with eBible Fellowship, told the AP.

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UPDATE: CNN has since taken a close look at 'Project Caravan,' the mobile movement preaching the end of the world. For more, watch the clip from CNN below.

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