Genesis 1 doesn't say God created darkness and most of the other references in the bible where it is said God creates darkness or darkness being mentioned is only symbolic to mean sin and the opposite which is light is symbolic of knowledge of God.
Imagine darkness being created at certain point in time and remember that the condition that must be there in the absence of darkness is always referred to as light and ask yourself, before darkness was created, was the light?
God who represented by three is Light, God is Spirit, God is love. God creates darkness and forms light and from that he assigned darkness to represent evil and light to represent that which is good. Therefore using the word good to represent Him not seen . This is after each day he ends it with...…. and God saw it was good.
Even the Son of man Jesus the temporal as that seen when called good teacher refused to be called good and gave glory to God and replied only God is good . Good defines God not seen.
The first three days of light and darkness. Each day he created darkness for 12 hours and for the remaining 12 he formed light . On the forth day he set the two temporal time keepers in the universe the Sun and the Moon.
In the end of time on the last day both the Sun and the moon will have served its temporal purpose .light to represent that which is good, God. And darkness to represent evil . Then the contrast between what is good and what is evil will not apply for there shall be no night there.(no evil)
And I saw no temple therein: for the Lord God Almighty and the Lamb are the temple of it. And the
city had no need of the sun, neither of the moon, to shine in it: for
the glory of God did lighten it, and the Lamb is the light thereof. And the nations of them which are saved shall walk in the light of it: and the kings of the earth do bring their glory and honour into it And the gates of it shall not be shut at all by day: for there shall be
no night there.Revelation21:22-25
He gives us a beautiful picture of that last day in the parable found in chapter 12. The chaste virgin bride of Christ clothed with the righteous of the glory of God. The two temporal time keepers under her feet
Revelation 12 And there appeared a great wonder in heaven; a woman clothed with the sun, and the moon
under her feet, and upon her head a crown of twelve stars.