actually the Bible says GOD created the heavens and the earth at exactly the same time. Gen, 1-1. Then in verse 2 HE says that the earth "became" without form & void. The word "was" is in the italic type, because no verb "to be" in Hebrew. The 6 days were for the surface only to make ready for mankind. And if you want to get in deep, each days work was called "good" except the 2nd, because nothing created on that day: only division made.