Genesis 1:8 KJV
And God called the firmament Heaven. And the evening and the morning were the second day.
Genesis 1:8, King James Version
In context
7 And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so.
8 And God called the firmament Heaven. And the evening and the morning were the second day.
9 And God said, Let the waters under the heaven be gathered together unto one place, and let the dry land appear: and it was so.