As crestfallen followers of a Caliphornia preacher who foresaw the world's end strained to find meaning in their lives, Harold Camping revised his apocalyptic prophecy, saying he was off by five months and the Earth actually will be obliterated on Oct. 21.Camping, who predicted that 200 million Christians would be taken to heaven Saturday before global cataclysm struck the planet, said Monday that he felt so terrible when his doomsday message did not come true that he left home and took refuge in a motel with his wife. His independent ministry, Family Radio International, spent millions -- some of it from donations made by followers -- on more than 5,000 billboards and 20 recreational vehicles plastered with the Judgment Day message.