What happened in the 1st Day of Genesis?
1st Day - God said, "Let there be Light..." [Genesis 1:3], and separated the light from the darkness, and this also calling us out of darkness into his Light, and so that the children of the Day and of the Night may be made manifest [1 Thessalonians 5:5].
But let us look in the Days with the Lord, even as a thousand years [2 Peter 3:1-18, especially vs 8] …
2 Peter 3:8 KJB - 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.
Psalms 90:4 KJB - For a thousand years in thy sight are but as yesterday when it is past, and as a watch in the night.
Since it is written that a day with the Lord is as a thousand years, then:
When Adam sinned, the darkness of this world's night fell upon it ...
What happened in the First day “with” God?
In the first 1,000 Years, after the fall of Adam [for Adam lived just short of the full day “with” God, Genesis 5:5, 2:17], in Genesis 3:15 we see the Everlasting Gospel go forward. ... "And God said,
Let there be light: and there was light." [Genesis 1:3];
What Light went forward in the first 1,000 years?
It was verily:
"... the light of the glorious gospel of Christ, who is the image of God... For God, who commanded the light to shine out of darkness, hath shined in our hearts, to [give] the light of the knowledge of the glory of God in the face of Jesus Christ." [2 Corinthians 4:4-6] shone forth with blazing power to save...
Genesis 3:15, the Gospel Light went forward ...
Adam died at 930 years of age [Genesis 5:5 KJB], just short of the "day with the LORD" [as per Genesis 2:17 KJB] as promised, dying "in the day".
The 2nd Day - God said, "Let there be a firmament in the midst of the waters, and let it divide the waters from the waters....divided the waters which [were] under the firmament from the waters which [were] above the firmament..." [Genesis 1:6-7]
In the Second 1,000 years, in the times of Abraham, the Gospel was made known unto him [Galatians 3:6-8], and so God called out a person who was to become a great nation, a multitude, a nation in whom all the earth would be blessed [Genesis 15:4-6, 18:18], calling Him and his out from Ur [Babylon], for "...The waters...are peoples, and multitudes, and nations, and tongues." [Revelation 17:5], and God separated the waters, A Heavenly body of waters, from the earthly body of waters, a heavenly [spiritual] peoples, from the earthly [carnal] peoples [Acts 7:2-5], and placed a space between them, and open division, clear, and without mixture, and from this Abraham would the seed come [Genesis 15:5, 18]...
The Third Day - God said, "Let the earth bring forth grass, the herb yielding seed, [and] the fruit tree yielding fruit after his kind, whose seed [is] in itself, upon the earth: and it was so." [Genesis 1:11]
In the Third 1,000 years, in the time of Moses, the same Gospel was also preached [Hebrews 4:2,6; Acts 7:38], and among the grass [Psalms 103:15; Isaiah 51:12; 1 Peter 1:24], that Nation of the line of Abraham, was brought forth from out of Egypt [a symbol of the earth [worldliness]], and Israel, was to be a fruit bearing Tree [Luke 13:6-7; John 1:48-50; Romans 11:17,24, etc], whose seed [the Gospel and Christ; Genesis 3:15] was in itself, came forth to bear much fruit...
The Fourth Day - 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: ... let them be for lights in the firmament of the heaven to give light upon the earth... 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.", thus the Sun, Moon and stars shone forth...
In the Fourth 1,000 years, The Seed Himself, Christ Jesus [Galatians 3:16], the glorious light of the Gospel [2 Corinthians 4:4-6], the Sun of Righteousness arose [Malachi 4:2], the blazing True Light [John 1:7-9, 8:12; Revelation 1:16] and was born into the world [Luke 3; Revelation 12:2-5], and the moon [the lesser light, like John the Baptist [John 1:6-8,15, 5:35], and the scriptures [Psalms 119:105; John 5:39; Luke 24:27; etc]] reflected His glory, and the true and unwandering stars shone to magnify Him [His people; Proverbs 4:18; Matthew 5:14; Revelation 1:6, etc; John, James, Peter, Paul, Apostles, Disciples, martyrs, saints, remnant; etc] each lighting the earth with their light, the lesser lights in submission to the Greater [John 1:4-9].
The Fifth Day [shortened] - God brought forth life from the waters and they were told to be fruitful and multiply...
In the Fifth 1,000 years, the waters of life, bring life, and multiplies and were fruitful, the Everlasting Gospel begins to spread to the whole inhabited world, every Nation... to every Creature [Matthew 28:19; Mark 13:10, 16:15; Acts 1:8; Colossians 1:23,27, to Jew and Gentile] and continues to fill the earth...
The Beast from the Sea arose [538-1798], Revelation 13:1 KJB
The 6th Day - God made perfect and sinless man, man in His own image, and a marriage… [shortened]
In the Sixth 1,000 years, mankind created in perfection, we shall see what the Everlasting Gospel of God, Divinity combined mysteriously with Humanity, what God, Christ, who is without sin can do in sinful human flesh... God recreates His image in us, “I will...” in fulfillment of His promises [Genesis 3:15; Jeremiah 31:31-34; Ezekiel 36:23-38, 37:23-28; 2 Corinthians 3:3; Hebrews 8:8-12, 10:16], He shall have the final Generation... the Harvest of Life, and the Marriage [Luke 12:36]... and the “...mystery of God should be finished...” [Revelation 10:7], Jesus is the “...author and finisher of our faith...” [Hebrews 12:2], the Alpha and Omega, the Beginning and the Ending, the First and the Last...
The Beast of the Earth, arose in the 6th 1,000 years, Revelation 13:11 KJB.
Notice that in the sixth day, there was a marriage, see Daniel 7:13-14; Luke 12:36; Isaiah 62:1-5
Notice, also Psalms 90:4 [and 2 Peter 3:8 KJB] again, and see not only that a “day with the LORD” is 1,000 years, but it also says, “and” “as a watch in the night”.
When Adam sinned, darkness fell upon this world, and therefore, there are 4 Watches in the Nighttime: Mark 6:48, thus each watch is also 1,000 years, thus from Adam to Jesus is again, 4,000 years, and then it is daytime, the Sun of Righeousness arises with healing in His wings, Malachi 4:2, etc. Thus there were only “2” working days left, and even satan knew it. For he must study prophecy also [see SoP/ToJ; {DA 115.1}; {20MR 175.5}], see Revelation 12:12, 14:15; Matthew 8:29 KJB
The 7th Day God rested…
The Seventh 1,000 years, all of saved humanity, is in atonement with God in Heaven... in rest...
Revelation 1:10, Hebrews 12:2; Psalms 90:4; Mark 6:48; Isaiah 46:9-10 [Declaring the End from the Beginning … In the beginning Genesis 1:1 KJB]
The 7th Day,
begins on earth, for the “dark” part of the day begins each new day, the “evening” portion, see Genesis 1, thus, since there is “no night” in heaven, it is then everlasting Day, which is the “rest” of the 7th Day [double entendre], see John 9:4; Revelation 21:25, 22:5
However, both Peter, Paul, John etc knew this also., see 2 Thessalonians 2:3; the phrase the “last days” [refer to the last “2” days of the great cosmic week with the LORD [ie, BC 4 to today] , and the final “Day of the LORD”, being the 7th.], see Acts 2:17; 2 Timothy 3:1; 2 Peter 3:3, which is why the disciples could speak of the “last days” 2,000 years ago, and it not be a mistake, nor error.
Thus the 7th Day the Sabbath, "the Lord's Day" is the ending of the Natural Week
Thus "the Day of the LORD" is the 7,000 Year, Great Sabbath, ending the great Cosmic week "with the LORD"