The second thousand year "day" is called Noah's day. Noah was born just 56 years into the second millennium (beginning with Adam's creation) and lived six years into the third. The 950 years of Noah's life was spent almost entirely in this second day and spanned nearly all of it.
Each of the millennial days has a set purpose. The first three millennial days seem to foreshadow the three fold gospel of the New Testament: death, burial and resurrection. Scripture tells us that Adam was told he would die if he ate of the forbidden fruit (which he did) and that death would come the same day that he ate of it. We read that before the millennial day was complete Adam had died. The first day then was the day of death. This corresponds to the first element of the gospel: the death of Jesus.
The second element of the gospel is the burial of Christ. It is not difficult to see the correlation between burial and the flood of Noah's day. Indeed, the earth was buried by the flood! The scripture alludes to this allegory in First Peter 3:20 and 21. While the first millennium's purpose focused on the single man Adam - his creation, dominion, fall, and judgement, the second millennial deals with the world wide consequence of sin's entrance into the world.
Mankind as a whole had fallen into the ravaging clutch of sin's demands and death was reigning supreme over the human race. Evil thoughts were the norm of Noah's generation and God was grieved over the condition of the world's population, so much so, that He devised judgment against this wickedness. But "Noah found grace in the eyes of the Lord".
To Noah was given the command to build a "salvation boat". This ark saved eight souls from the flood's judgemental waters allowing the continuation of man's existence on earth. However, the continued life afforded by the ark was granted only through a "baptismal judgement" of sin. That is to say that the rampant sin that had enveloped the world had to be judged, yet God gave a second chance for human existence by this plan of salvation for Noah's millennial day.
Throughout scripture the concept of burial is a strong theme. The most notable event of the second millennial day was the flood and the most notable person of the day was Noah. The second day then, more than anything else, is associated with the baptism (burial) of the entire earth; that is the flood. Of all the spiritual typology of this thousand year period perhaps the most striking is the sometimes little observed consequence of this particular judgement.
The result of this watery judgement was that every man mentioned from Adam through Noah (except for Noah, of course) died by the time of the flood. Even Methuselah, the oldest man who ever lived, died; and as if to emphasize the point, he died the same year that the flood came! However, just as significantly, after the flood not one person in the lineage from Noah to Abraham died during the remainder of this millennial day! This is truly the nature of God's judgement at work; "old things are past away behold all things become new". His judgements are not the work of an angry, out of control deity but of a righteous judge executing His divine justice and bringing to pass His divine plan. He is the God of second chances; the second millennial day is a wonderful illustration of that. He also has a second chance and divine plan for each of us! Make it your life's ambition to find those and you will not be disappointed.