Clearly day and night were in the beginning. God saw the earth as darkness and on the first day created light and called the light day and then divided into darkness which he called night. Can it be any clearer?
001:001 In the beginning God created the heaven and the earth.
001:002 And 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.
001:003 And God said, Let there be light: and there was light.
001:004 And God saw the light, that it was good: and God divided the light from the darkness.
001:005 And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.