Yes that is your opinion. As Catholics we are bound to believe that God could very well have created all things in heaven and on earth in the timeframe you suggest.
However, we are permitted to believe that God created all things, both physical and spiritual out of nothing. That if He chose to create the earth, and populate it over millions of years, and that some animals would become extinct, others would evolve over time, by His will, and that at some point in history God created an immortal soul with free will and and infused it into our first human parent, (after all what separates us from the animals is that we have an immortal soul, free will and a rational mind, well at least some of us have a rational mind.) Nothing in creation is without God as it’s primary source,
In an address given to the Pontifical Academy of Sciences in 1941, when Pope Pius XII listed certain “elements which must be retained as certainly attested by the sacred author (of Genesis), without any possibility of an allegorical interpretation.” These elements in question are:
[quote:3q5j1qki]1.The essential superiority of man in relation to other animals, by reason of his spiritual soul.
2.The derivation of the body of the first woman from the first man.
2.The impossibility that the father and progenitor of a man could be other than a human being, i.e., the impossibility that the first man could have been the son of an animal, generated by the latter in the proper sense of the term. In context, the Pope said, “Only from a man can another man descend, whom he can call father and progenitor” Acta Apostolicae Sedis, 1941, pg. 506. On other questions concerning the origin of man, the pontiff said we must wait for more light “from science, illumined and guided by revelation.” Augustine Bea of the Biblical Institute believed these “other questions” still open include the degree in which a lower species may have cooperated in the formation of the first man, the way in which Eve was formed from Adam, and the age of the human race.[/quote:3q5j1qki]
Further in the Encyclical Humani Generis, published in 1950, Pius XII expressed himself at length on the subject of evolution. This was the first time in history that the Holy See had officially treated in a document of such authority the question of the evolutionary origin of the human body. The passage should be quoted in detail:
[quote:3q5j1qki]”The Magisterium of the Church does not forbid that the theory of evolution concerning the origin of the human body as coming from preexistent and living matter – for the Catholic faith obliges us to hold that human souls are immediately created by God – be investigated and discussed by experts as far as the present state of human sciences and sacred theology allows.”[/quote:3q5j1qki]
So I think I side with the Pope on this one. I do not deny that 6/24hr days could have been used by God, but I am not obliged to hold this De Fide. I am as a Catholic obliged to certain principles which the Pope, the Pontifical Biblical Commission and the Pontifical Academy of Sciences all ove which he oversaw and published under his authority have pronounced.
For a full examination of the source document, please go to the following link, as this was taken from one of the texts of the late Fr. John Hardon, S.J. and written before the Second Vatican Council. Fr. Hardon was well respected before and after the Council. Fr. Hardon was also hated and ridculed by liberal and modernist theologians for his orthodoxy. In most of the writings which pre-date the Council you will have to remember, that when he simply mentions the Vatican Council, he is referring to Vatican I. Since Vatican II had not yet occured when he was writing much of what is posted there was no need to distinguish it as Vatican I, as it was the only Vatican Council.