That’s the date the rapture will occur, according to this biblical scholar. His reasoning is as follows, and I’m sorry I couldn’t put it in block quote form, but blogger’s software is screwed up.

“The number 5, Camping concluded, equals “atonement.” Ten is “completeness.” Seventeen means “heaven.” Camping patiently explained how he reached his conclusion for May 21, 2011. 

“Christ hung on the cross April 1, 33 A.D.,” he began. “Now go to April 1 of 2011 A.D., and that’s 1,978 years.”

Camping then multiplied 1,978 by 365.2422 days – the number of days in each solar year, not to be confused with a calendar year.

Next, Camping noted that April 1 to May 21 encompasses 51 days. Add 51 to the sum of previous multiplication total, and it equals 722,500.

Camping realized that (5 x 10 x 17) x (5 x 10 x 17) = 722,500.”

Full article here.

I must say, this is inspired. The Christians have to find some way to beat out the Mayans doomsday prophecies, and now they’re offering doomsday a whole six months earlier. This may well increase their market share.