George Keller missed his Leap Day birthday party by a few hours, the St. Louis Post-Dispatch reported. The family decided to go ahead with the party anyway.
"It's actually pretty awesome to live 100 years to the actual day," his daughter, Mary Sue Schoellhorn, said. "I think he would have been pleased."
While Wednesday was technically only Keller's 25th birthday going by the calendar, the family had 100 candles on the cake. He was represented at the party with an empty chair draped with a sash that said "100 Years Old."
Keller's survivors include three children, 14 grandchildren, 21 great-grandchildren and one great-great-grandson. Many of his descendants, who had come to the St. Louis suburb of Columbia for his birthday, were at his bedside in his last hours.
His wife, Roberta, died in 2001 and one of his daughters in 2008.
Keller worked for General American Life Insurance for half a century, retiring at 65.
"I think I'm the luckiest guy in the world," he told the Post-Dispatch in a profile that was published on his birthday.