Those seven days were significant. They may have more than one significance. One of them, however, connects with a prophetic time formula.
For a thousand years in thy sight are but as yesterday when it is
past, and as a watch in the night. (Psalm 90:4, KJV)
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. (2
Peter 3:8, KJV)
Each day in God's sight is as a thousand years, and vice versa. Many people mistakenly assume that this very precise time equation simply means that time is not important to God. If it were not important, why would He bother to give us such a clear A = B and B = A definition statement?
Peter actually wrote this definition statement within the context of earth's week, including the Flood.
And saying, Where is the promise of his coming? for since the fathers
fell asleep, all things continue as they were from the beginning of
the creation.
For this they willingly are ignorant of, that by the word of God the
heavens were of old, and the earth standing out of the water and in
the water: Whereby the world that then was, being overflowed with
water, perished: But the heavens and the earth, which are now, by the
same word are kept in store, reserved unto fire against the day of
judgment and perdition of ungodly men. (2 Peter 3:4-7, KJV)
Those are the verses just prior to Peter's declaration of the thousand-year-day principle. He speaks of creation, of the word of God during those days of creation, and mentions specific events of the creation connected with days 2 and 3 of creation week.
If we look at the generations from Adam to Noah and follow the years of the lives of these patriarchs, we discover that the Flood occurs well into the second millennium after creation. Considering each day of creation to represent a thousand years (which is also why Adam died in the "day" that he ate the forbidden fruit), the Flood would have come on the "second day." And this is exactly what Peter seems to be saying.
Notice carefully:
Day 2/3 of Creation |
Fulfillment of Prophecy |
For this they willingly are ignorant of, that by the word of God the heavens were of old, and the earth standing out of the water and in the water: (vs. 5) |
Whereby the world that then was, being overflowed with water, perished: (vs. 6) |
Did the Flood come during creation week? Obviously not. Why, then, does Peter indicate so?
...and Peter seems to understand that what he has just said will perplex many minds, so he makes the prophetic time formula plain in the next verses, saying...
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.
(vs. 8)
Just as creation week prophesied of seven millennia to come in the history of this earth, so also do the seven days of Noah's waiting in the ark. Noah waited seven days before the destruction of the earth came and sinners were wiped away. So also will the earth wait for seven millennia for the final destruction of sin and sinners in the fires of hell.
Jesus also referenced this time of Noah and applied it to the time of the end--the end of earth's history.
But of that day and hour knoweth no man, no, not the angels of heaven,
but my Father only. (Matthew 24:36, KJV)
But as the days of Noe were, so shall also the coming of the Son of
man be. (Matthew 24:37, KJV)
For as in the days that were before the flood they were eating and
drinking, marrying and giving in marriage, until the day that Noe
entered into the ark, (Matthew 24:38, KJV)
And knew not until the flood came, and took them all away; so shall
also the coming of the Son of man be. (Matthew 24:39, KJV)
Conclusion
The seven days in the ark represent the seven millennia of probationary time allotted to the sin experiment on earth. However, this may not be their only significance.