Does Genesis teach a young earth, and did the 1909 Biblical Commission settle the age of creation?

I have been a stalwart for the young earth that the Bible teaches for the last 23 years, though my writing on it is scattered rather than in one book; the closest is Scientific Heresies. On the debate, Timothy Gordon leaned on the 1909 Pontifical Biblical Commission decision, and that is his strongest angle, because even our side has to admit the PBC made a big mistake. The PBC asked itself whether the day of Genesis 1 can be taken as a 24-hour period or as a certain period of time, and it answered yes to both. That is not an answer; it is an abdication, because it cannot be both 24 hours and a long period at the same time. And they had the information to answer correctly: about two dozen of the Fathers, east and west, said the days were 24 hours. Only Origen, who has a poor reputation, and Augustine in his later career said otherwise, and the PBC got its certain period of time from Augustine, who loved to allegorize. Under pressure from the Catholic evolutionists already active by 1910, the PBC left the door open, and every Catholic evolutionist since has walked through it.