A preacher who spent millions of dollars to publicize his message of impending global doom has for the first time acknowledged his apocalyptic prophecy was wrong.

In a letter posted on his independent ministry's site on Thursday, 90-year-old Harold Camping told his followers he has no evidence the world will end anytime soon, and he isn't interested in considering future dates.

"We realize that many people are hoping they will know the date of Christ's return," Camping wrote. "We humbly acknowledge we were wrong about the timing."

Camping's Family Radio International broadcasts his messages from the nonprofit's headquarters in a squat building near the Oakland airport. In recent years, the organization spent millions — some of it from donations made by followers — putting up thousands of billboards plastered with his Judgment Day prediction.

Many listeners were crestfallen May 21 when the Rapture did not occur, particularly those who had quit their jobs or donated some of their retirement savings or college funds to get out the word.

That evening, Camping revised his prophecy, saying he had been off by five months.

Several weeks later, he was hospitalized after suffering a mild stroke but continued spreading the word through his website and radio show that natural disasters would destroy the globe.

Thursday, Camping alerted his flock that he had stopped looking for new dates, and would concentrate on deepening his faith through rereading the Scriptures.

"God has humbled us through the events of May 21," he wrote. "We must also openly acknowledge that we have no new evidence pointing to another date for the end of the world."