Day 1
God created LIGHT.
Day 2
God separated the waters.
Day 3
God separated the land and the sea and created plants.
Day 4
God created the lights of the heavens.
Day 5
God created the birds and the fish.
Day 6
God created the land animals and man.
Day 7
God rested.
Fiat
There is no passage of time or process involved.
Why did God make the Heavenly Bodies?
Separation, Regulation, Illumination.