"'That's one small step for man, one giant leap for mankind,' said Neil Armstrong, the first man to walk on the moon, on July 21, 1969."
But as it turns out there's a minor technical issue about the exact date, apparently. "NASA's official time is kept in GMT (Greenwich Mean Time), but Americans
remember the moment as occurring on the night of July 20, 1969 because
of the time change," according to THIS New York Daily News story.