Despite what is taught by some today, early Bible students and writers did sometimes see the creation of Genesis 1:1In the beginning God created the heaven and the earth.
See All... as a creation that preceded the six-day creation. Augustine of Hippo, though not any sort of authority for truth, demonstrates the existence of this belief long ago. He wrote his Confessions in 397 AD. In them (12th Book, 13th Chapter), he comments on the formless earth of Genesis 1:2And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
See All... and God "not stating on what day Thou didst create these things." He also refers to two creations of Genesis 1:1In the beginning God created the heaven and the earth.
See All... as "the one heaven, but the heaven of heavens, the other earth, but the earth invisible and formless" and that these were created "without mention of days."

Of the heaven, he states: "And when on the second day the firmament [that is, heaven] is recorded to have been created, and called heaven, it suggests to us of which heaven He spake before without mention of days." His wording is difficult, but he is clearly teaching that there were two heavens: God’s heaven he calls the "intellectual heaven" and shows that it is created without mention of days at some time in the past while the heaven we see as the present universe was created on the second day of the six-day creation week. This same belief is found in other early Christian writings.