Genesis 1:5-7

5 God called the light “day,” and the darkness He called “night.” So there was evening and there was morning — one day.

6 Then God said, “Let there be an expanse in the midst of the water! Let it be for separating water from water.”

7 So God made the expanse and it separated the water that was below the expanse from the water that was over the expanse. And it happened so.