I read the original.
Listen to what Augustine says:
What kind of days these are is difficult or even impossible for us to imagine, to say nothing of describing them.
So, as he points out, not literal days. He goes on to say:
In our experience, of course, the days with which we are familiar only have an evening because the sun sets, and a morning because the sun rises; whereas those first three days passed without the sun, which was made, we are told, on the fourth day. The narrative does indeed tell that light was created by God…. But what kind of light that was, and with what alternating movement the distinction was made, and what was the nature of this evening and this morning; these are questions beyond the scope of our sensible experience. We cannot understand what happened as it is presented to us; and yet we must believe it without hesitation.”
Again, he makes it clear that these could not be literal days, but that we must accept it as it is. Note he said this we must believe without hesitation. While he believed that the Earth was a few thousand years old, he also asserted that we must be willing to change our opinions if evidence indicated.
With the scriptures it is a matter of treating about the faith. For that reason, as I have noted repeatedly, if anyone, not understanding the mode of divine eloquence, should find something about these matters [about the physical universe] in our books, or hear of the same from those books, of such a kind that it seems to be at variance with the perceptions of his own rational faculties, let him believe that these other things are in no way necessary to the admonitions or accounts or predictions of the scriptures. In short, it must be said that our authors knew the truth about the nature of the skies, but it was not the intention of the Spirit of God, who spoke through them, to teach men anything that would not be of use to them for their salvation.
De Genesi ad literam, 2:9
In matters that are so obscure and far beyond our vision, we find in Holy Scripture passages which can be interpreted in very different ways without prejudice to the faith we have received. In such cases, we should not rush in headlong and so firmly take our stand on one side that, if further progress in the search for truth justly undermines our position, we too fall with it.
De Genesi ad literam
Creationists need to brush up on their church history not to mention the scriptures themselves. As you now see, St. Augustine asserted that the days of creation could not be literal days.
St. Augustine believed that a few thousand years were sufficient for the gemmae created by God to bring forth all living things. He was in error on that, although he did recognize that God created the earth to bring forth life, something that creationists have repeatedly refused to accept in scripture.
Scripture has stated that the earth brought forth the crops and the trees causally, in the sense that it received the power of bringing them forth.
De Genesi ad literam
Let God be God, and accept His word as it is, rather than as you'd like it to be.