If I understood you correctly, I will attempt to restate what you gave, in that you think that as students of scripture, we cannot know for how long Adam was in the Garden of Eden before being expelled and could therefore be 'ages' (thousands of years, millions of years,etc) of time?
If that is your premise, and I understood you correctly, that would be an incorrect position to hold.
Notice scripture please:
Gen 5:1 This is the book of the generations of Adam. In the day that God created man, in the likeness of God made he him;
Gen 5:2 Male and female created he them; and blessed them, and called their name Adam, in the day when they were created.
Gen 5:3 And Adam lived an hundred and thirty years, and begat a son in his own likeness, after his image; and called his name Seth:
Gen 5:4 And the days of Adam after he had begotten Seth were eight hundred years: and he begat sons and daughters:
Gen 5:5 And all the days that Adam lived were nine hundred and thirty years: and he died.
Genesis 5:1, Adam was created in the 6th Day, see Genesis 1 & 2.
Genesis 5:2, agrees with Genesis 1:27c., and further agrees with Genesis 2:7-25.
Genesis 5:3 relates that Adam, after 130 years of life, had a child by the name of "Seth". "Seth" came after "Cain and Abel", as per Genesis 3:20, 4:1,2, 25,26.
Genesis 5:4 relates that Adam lived 800 years longer after "Seth" was born. Thus the total life span of Adam being alive is 930 years old, as per Genesis 5:5.
Genesis 5:5 seals the range to 930 years for the entire lifespan of Adam, from the moment of coming alive in creation to ceasing to live, as it says, quite clearly, "all the days that Adam lived", which would include the "days" (Genesis 1:14) in the Garden before sin, up to the very point of Genesis 2:7 in his coming alive as a living soul/person/creature/being.
Therefore, we know, from the text, and without guessing at all, that
Adam was in that Garden of Eden sometime before his 130th year. We know that
Adam was out of the Garden of Eden in at least his 130th year, seeing that "in the process of time" (Genesis 4:3) took place with Cain and Abel to be both born and to grow up enough to be a "tiller of the ground" (farmer) and also to raise livestock (sheep), and for sheep to be born and fruit to grow out of the ground; Genesis 4:2.
Yet, even though we do not know the exact number of days, weeks, months or years Adam was in the Garden of Eden, we do know it could not have been 130 years. For "all that days that Adam lived" were 930, which includes the time (whatever it was) in the Garden of Eden, and before Cain and Abel. Nowhere does any text say that all the days that Adam lived outside of the Garden. That would be eisegesis and false apriori nowhere represented by any text of scripture.
