Rescheduling the apocalypse

According to Harold Camping (who I've never heard of before, but that's probably only because I wasn't paying attention), the world is not going to end in December of 2012, but more that 1.5 years earlier, on May 21, 2011.

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.

Or put into words: (Atonement x Completeness x Heaven), squared.

I'm teaching a course on early Jewish and Christian apocalypticism this semester, so Camping's story has won a spot on my syllabus, just for being timely. But I'm wondering whether he took into account the 10 days lost in the switch from the Julian to the Gregorian calendar? Because it doesn't sound like it. And the last time, his calculations were off a bit (Sept. 6, 1994!), and you wouldn't want to make that mistake twice . . .