Pay close attention wondering because I am going to give you the correct answer to that question.
First let me tell you this. It was not Cains sister that he took for a wife. No pay attention please this is slightly difficult to grasp if you can´t let go of the rubbish you heard in church.
Gen 1:24 And God said, Let the earth bring forth the living creature after his kind, cattle, and creeping thing, and beast of the earth after his kind: and it was so.
Gen 1:25 And God made the beast of the earth after his kind, and cattle after their kind, and every thing that creepeth upon the earth after his kind: and God saw that it was good.
Gen 1:26 And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.
Gen 1:27 So God created man in his own image, in the image of God created he him; male and female created he them.
Gen 1:28 And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.
Gen 1:29 And God said, Behold, I have given you every herb bearing seed, which is upon the face of all the earth, and every tree, in the which is the fruit of a tree yielding seed; to you it shall be for meat.
Gen 1:30 And to every beast of the earth, and to every fowl of the air, and to every thing that creepeth upon the earth, wherein there is life, I have given every green herb for meat: and it was so.
Gen 1:31 And God saw every thing that he had made, and, behold, it was very good. And the evening and the morning were the sixth day.
That is the end of creation more or less but not really the end. here´s why that is true.
Gen 2:1 Thus the heavens and the earth were finished, and all the host of them.
Gen 2:2 And on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made.
Gen 2:3 And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made.
Gen 2:4 These are the generations of the heavens and of the earth when they were created, in the day that the LORD God made the earth and the heavens,
Gen 2:5 And every plant of the field before it was in the earth, and every herb of the field before it grew: for the LORD God had not caused it to rain upon the earth, and there was not a man to till the ground.
Generations? How does generations fit in with 6 days? Is that saying the earth was not created in 6 days as we understand da to mean? Exactly what it is doing. Look.
Gen 2:7 And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.
Gen 2:8 And the LORD God planted a garden eastward in Eden; and there he put the man whom he had formed.
But wait? How can we reconclie both of these?
Gen 1:27 So God created man in his own image, in the image of God created he him; male and female created he them.
AND
Gen 2:7 And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.
Unless they are the same man?
Well, don´t let the people in the churches do the reconciling here because they don´t know how. Ok, i grant it that many of them are at least aware of the difference here and they have a term they use to describe it they call "pre-admic" man. Not exactly accurate but stioll the truth.
Basically Adam was not the first man created according to the bible. Adam was the first man created considering the redemption plan God had in mind. Adam was the first man that was going to be subjected to the wiles of the devil.
so basically when God tossed Cain out of the garden there were already other tribes wondering the earth. How long had they been there before God made Adam? Who knows? There isn´t a single clue in the bible its self, but the earth is ripe with answers. It´s just nearly impossible to put all those clues together in such a fashion that the question is satisfactorily answered.
Consider this truth.
The evening and the morning was the sixth day.
What Hebrew word was used to translate or translitrate into the English word "day"? Nevermind the other terminology about "evening and the morning" the key word to focus in on here is "day".
The Hebrew word is Yom. strongs tells us that Yom means this:
yôm
OR
yome
From an unused root meaning to be hot; a day (as the warm hours), whether literally (from sunrise to sunset, or from one sunset to the next), or figuratively (a space of time defined by an associated term), (often used adverbially): - age, + always, + chronicles, continually (-ance), daily, ([birth-], each, to) day, (now a, two) days (agone), + elder, X end, + evening, + (for) ever (-lasting, -more), X full, life, as (so) long as (. . . live), (even) now, + old, + outlived, + perpetually, presently, + remaineth, X required, season, X since, space, then, (process of) time, + as at other times, + in trouble, weather, (as) when, (a, the, within a) while (that), X whole (+ age), (full) year (-ly), + younger.
So now I ask this. With all thos epossible meanings for the word Yom, which is the ideal word to use from the English?
Well consider verse Gen 2:4 These are the generations of the heavens and of the earth when they were created,
What kind of a 24 hour day equates to "generations"? Well none is the correct answer so that leaves the original question unanswered, sort of.
But suppose that the churchs that lie ans say it is either six 24 hour days or 6 thousand years (adopting that belief from the two verses that state 1000 years is as a day with God)
are actually wrong, and I say they are. Suppose here that God is simply telling us that he is timeless and evne though a thousand years go by no real time passed for Him.
Also notice on both the 5th and 6th days how God handles creation. Telling elements to produce things that have life. That isn´t quite the picture they tried to get into our heads in Sungodday school at church. They painted this picture of God speaking everything into existance all at once. God said He told the water to bring forth life and that he told the ground to bring forth life. Doesn´t that leave room for the secularist term "evolution"? a bit open? Yes it does to be quite honest.
Do you see what I am attempting to tell you?