God said, "Let there by lights in the expanse of the sky to separate day from night; they shall serve as signs for the set times - the days and the years; and they shall serve as lights in the expanse of the sky to shine upon the earth." And it was so. God made the two great lights the greater light to dominate the day and the lesser light to dominate the night, and the stars. And God set them in the expanse of the sky to shine upon the earth, to dominate the day and the night, and to separate light from darkness. And God saw that this was good. And there was evening and there was morning, a fourth day.
Genesis 1:14 - 19