I got into it with one of my seminary professors about this, so it is funny you started this thread. The fact is there was no sun on the first day.But there was evening and morning. So,what was evening and what was morning? Is evening darkness and morning light? Well, yes according to our understanding of day and night. The Bible tells us that the light God called day and the darkness he called night. So what was the light source on the first day? I submit that the light source was the Son of God as the Word.
John 8:12
Then spake Jesus again unto them, saying, I am the light of the world: he that followeth me shall not walk in darkness, but shall have the light of life.
John 9:5
As long as I am in the world, I am the light of the world.
John 5:35
He was a burning and a shining light: and ye were willing for a season to rejoice in his light.
John 1:5
And the light shineth in darkness; and the darkness comprehended it not.,
We learn that on the first day, God divided the light from the darkness, and called light day and called darkness night. So....we see night and day created, buuut, we do not see time yet, untiiiil the designation of evening and morning. As I read the scriptures, I see time portrayed several ways.
John 11:9
Jesus answered, Are there not twelve hours in the day? If any man walk in the day, he stumbleth not, because he seeth the light of this world.
Psalm 90:4
For a thousand years in thy sight are but as yesterday when it is past, and as a watch in the night.
2 Peter 3:8
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.
So we end up with more questions than answers to the question.
Is it twelve hours? Is it twentyfour hours.? Is it a thousand years?