Second, when Michael and Kay are dancing at Anthony’s party, she says, “You said the Corleone Family would be completely legitimate in five years. That was seven years ago.” Since the party is set in late 1958, it means that Michael and Kay were married in 1951.
This would also assume that Mike and Kay were married immediately in 1951, yet Anthony was probably about three when Vito died, and then he was seven three years later in 1958.
