The Bible also explains
several days as "the day" at (Genesis 2:4)
These are the generations of the heavens and the earth when they were created, in
the day that Yahweh God made earth and heaven.
--Legacy Standard Bible
Genesis 2:4 - Man and Woman in the Garden
Day 1: God made light reach earth’s surface, resulting in night-and-day cycles.
Day 2: God formed an expanse, or a division between water on earth’s surface and water high above its surface. The sky and the sea.
Day 3: God made dry land appear. He also created the vegetation.
Day 4: God made the sun, moon, and stars visible as distinct luminaries from the earth’s surface.
Day 5: God created aquatic life and flying creatures.
Day 6: God created land animals and humans.
For a thousand years are in your eyes just as yesterday when it is past, Just as a watch during the night. --Psalm 90:4
But, beloved, be not ignorant of this one thing: that
with the Lord one day is as a thousand years, and a thousand years as one day. --2 Pet. 3:8 KJ
In addition, on the first creative day, “God began calling the light Day, but the darkness he called Night.” (Genesis 1:5)
Here, only a portion of a 24-hour period is defined by the term “day.” Certainly, there is no basis in Scripture for stating that each creative day was 24 hours long.
The fact is that the Hebrew word translated “day” can mean various lengths of time, not just a 24-hour period. For example, when summarizing God’s creative work,
Moses refers to Several creative days as one day. (Genesis 2:4).