The 90-year-old Alameda preacher who convinced hundreds of followers that the world was going to end last May now acknowledges he was wrong.

"Events in the last year have proved that no man can be fully trusted," Harold Camping wrote in a letter Thursday to listeners of his evangelical Family Radio program, "Open Forum." "Even the most zealous of us can be mistaken."

Camping had predicted that the rapture would occur at 6 p.m. May 21, 2011. Believers would rise to heaven while the rest would be left to wander a godforsaken planet until Oct. 21, when Camping promised a fiery end to the world.

But nothing happened.

Standing on his front porch the next morning, Camping said he was "flabbergasted" that the rapture he'd predicted had not come.

He promised an explanation after prayer and talks with friends. But Camping had a stroke less than a month later and was hospitalized until September. Once he was released, Camping said both the rapture and the end of the world would take place Oct. 21.

"I really am beginning to think as I've restudied these matters that there's going to be no big display of any kind," Camping said at the time. "The end is going to come very, very quietly."

Once again, the date came and went without incident.

"God has humbled us through the events of May 21," Camping wrote Thursday. "We have learned the very painful lesson that all of creation is in God's hands and he will end time in his time, not ours!

"We humbly acknowledge we were wrong about the timing."