For example, before the first creative “day” started, light from the already existing sun was somehow prevented from reaching the earth’s surface, possibly by thick clouds. (Job 38:9) During the first “day,” this barrier began to clear, allowing diffused light to penetrate the atmosphere.a

On the second “day,” the atmosphere evidently continued to clear, creating a space between the thick clouds above and the ocean below. On the fourth “day,” the atmosphere gradually cleared to such an extent that the sun and the moon were made to appear “in the expanse of the heavens.” (Genesis 1:14-16) In other words, from the perspective of a person on earth, the sun and moon began to be discernible. These events happened gradually.