If I may weigh in on this.  I think a critical principle is that contained within Provendentissimum Deus of Pp. Leo XIII (blessing with Papal charism a teaching of Augustine).  

In it, he states that we are to hold to the literal meaning of scripture unless compelled to depart from it by reason:

15. But he must not on that account consider that it is forbidden, when just cause exists, to push inquiry and exposition beyond what the Fathers have done; provided he carefully observes the rule so wisely laid down by St. Augustine-not to depart from the literal and obvious sense, except only where reason makes it untenable or necessity requires;(40) a rule to which it is the more necessary to adhere strictly in these times, when the thirst for novelty and unrestrained freedom of thought make the danger of error most real and proximate.


From this, I think it is important, not to try to draw some universal conclusion about the age of the Earth or the details of creation, but rather to see that, since this is taught infallibly to be a matter of reason, it is possible that we, having imperfect faculties of reason might not reach the same conclusion as each other.  Further, reason must operate upon knowledge, and so I, or you, possessing different knowledge than another person of good will, might not reach the same conclusion as they.  

I, personally, see no issue (My reason does not protest) with God doing any good miracle, therefore my reason does not compel me to question whether Jonah spent time in a whale stomach.  Scripture presents it as miraculous, miracles are possible, miracles are part of recorded history, and belief in (continuing) miracles is an element of the faith.  Ergo, according to the principle in PD, I believe the Jonah story.  

On the matter of the age of the universe, data exists which points to a very old age.  It seems internally consistent, for the most part.  Therefore, if a Catholic applied his or her reason to it, and determined that it was compelling, they would be obliged to depart from the literal and obvious sense in this and only this area.  If a Catholic applied his or her reason to the question and came to the opposite conclusion, they would be bound to hold to the literal sense.  As the good Pope said, we have to be strict about this.  

And, as I'm sure everyone knows, this principle is limited in PD and later docuмents, to (at most) the most ancient books of the Old Testament, with a brick wall of dogma surrounding the historicity of both the New Testament and the majority of the Old Testament giving contemporaneous Jєωιѕн history.  Personally, I find the Abraham narrative of such remarkable harmony with secular archaeology and history that there seems no reason to question it, so I'd say that, for me, I find no reason to want this principle for anything in scripture starting with Abraham.  Except perhaps for the multiple accounts of disguising wives as sisters.  I'm thinking that probably happened only once.  But, people are funny.