Harold Camping has presented several numerological^[15] arguments, or biblical “proofs”, in favor of the May 21st end time. A civil engineer by training, Camping states he has attempted to work out mathematically-based prophecies in the Bible for decades. In an interview with the San Francisco Chronicle he explained “…I was an engineer, I was very interested in the numbers. I’d wonder, ‘Why did God put this number in, or that number in?’ It was not a question of unbelief, it was a question of, ‘There must be a reason for it.’ “^[16]

Another argument^[18] that Camping uses in favor of the May 21st date is as follows:As early as 1970, Camping dated the Great Flood to 4990 BC.^[17] Taking the prediction in Genesis 7:4 (“Seven days from now I will send rain on the earth”) to be a prediction of the end of the world, and combining it with 2 Peter 3:8 (“With the Lord a day is like a thousand years, and a thousand years are like a day”), Camping concludes that the end of the world will occur in 2011, 7000 years from 4990 BC.^[6] Camping takes the 17th day of the second month mentioned in Genesis 7:11 to be the 21st May, and hence predicts the rapture to occur on this date.^[6]

1. According to Camping, the number five equals “atonement”, the number ten equals “completeness”, and the number seventeen equals “heaven”.
2. Christ is said to have hung on the cross on April 1, 33 AD. The time between April 1, 33 AD and April 1, 2011 is 1,978 years.
3. If 1,978 is multiplied by 365.2422 days (the number of days in a solar year, not to be confused with the lunar year), the result is 722,449.
4. The time between April 1 and May 21 is 51 days.
5. 51 added to 722,449 is 722,500.
6. (5 × 10 × 17)² or (atonement × completeness × heaven)² also equals 722,500.

Thus, Camping concludes that 5 × 10 × 17 is telling us a “story from the time Christ made payment for our sins until we’re completely saved.”^[16]

Camping has not been precise about the exact timing of the event, saying that “maybe” we can know the hour.^[19] He has suggested that “days” in the Bible refer to daylight hours particularly.^[19] Another account says the “great earthquake” which signals the start of the Rapture will “start in the Pacific Rim at around the 6 p.m. local time hour, in each time zone.”^[20]

In Camping’s book 1994?, self-published in 1992, he predicted that the End Times would come in September 1994 (variously reported as September 4^[14] or September 6^[21]). When the Rapture failed to occur on the appointed day, Camping said he had made a mathematical error.