A careful read of Genesis chapter 1 tells us that a day unto the Lord in his creation process was not the same as a day is to us today. Let us examine it.
Genesis 1:1-5
1 In the beginning God created the heaven and the earth.
2 And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
3 And God said, Let there be light: and there was light.
4 And God saw the light, that it was good: and God divided the light from the darkness.
5 And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.
The first thing to note is that the heaven and earth were created in what is known as "the beginning". This was before God put light upon the earth as shown in verse 3. God's dividing of the light into night and day constituted a day. Notice how the earth and heaven were created before the light was introduced onto the earth. Thus the heaven and earth were not created within the 7 days of creation.
The next question you need seriously ask is, "What is the source of the light that God introduced on the earth to start counting days?" Was it the sun or was the light coming from elsewhere? If we go down to the events of the 4th day of creation we read:
Genesis 1:14-19
14 And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years:
15 And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so.
16 And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also.
17 And God set them in the firmament of the heaven to give light upon the earth,
18 And to rule over the day and over the night, and to divide the light from the darkness: and God saw that it was good.
19 And the evening and the morning were the fourth day.
Now we are seeing that on the 4th day (which consisted of night and day) God creates other lights to place in the firmament of heaven to give light for night and day upon the earth. Why would he need other lights to give light upon the earth when he already had light upon the earth since the 1st day of creation? Obviously the lights on the 4th day are the sun and moon and stars which were to continuously give light upon the earth. So, what is the source of the light God is using for his days of creation? Is one day unto the Lord the same as one day unto man? Latter-day revelation has answered these questions.
Abraham 3:4
4 And the Lord said unto me, by the Urim and Thummim, that Kolob was after the manner of the Lord, according to its times and seasons in the revolutions thereof; that one revolution was a day unto the Lord, after his manner of reckoning, it being one thousand years according to the time appointed unto that whereon thou standest. This is the reckoning of the Lord’s time, according to the reckoning of Kolob.
This verse tells us that the Lord's time is reckoned after a star called Kolob. One day to the Lord is equivalent to 1000 years of our current time. Thus if the creation was reckoned according to the Lord's time, then the 7 days of creation would need to have lasted 7000 years. The following verse verifies that the time was being calculated according to the Lord's time and not man's time.
Abraham 5:13
13
But of the tree of knowledge of good and evil, thou shalt not eat of it; for in the time that thou eatest thereof, thou shalt surely die. Now I, Abraham, saw that it was after the Lord’s time, which was after the time of Kolob; for as yet the Gods had not appointed unto Adam his reckoning.
This verse tells us that Adam was under the Lord's time and not man's time even at the time he was commanded to not eat of the tree of knowledge of good and evil. This was after the time of creation and thus the creation periods were after the Lord's time since God had not yet give Adam his time of reckoning. This would also account for why Adam lived to be 930 years of our time but still died in the "day thou eatest thereof" (Genesis 2:17).
The Apostle Peter taught us:
2 Peter 3:8
8 But, beloved, be not ignorant of this one thing, that one day is with the Lord as a thousand years, and a thousand years as one day.
