Did God create the whole universe, including the original plants, animals, and first two people (Adam and Eve) in six literal 24-hour days? Or did creation take place over millions of years?
To answer that, we should remember that the original readers of Genesis were not scientists or Hebrew scholars. Rather, they were former slaves -- mostly uneducated -- on their way to the Promised Land. The fathers were commanded to teach their children (Deuteronomy 6:1–7), so the Hebrew language in Genesis 1 must have been very clear to the common people, even to children.
When we look carefully at Genesis 1, in Hebrew or even in English, it is clear that God created everything in six literal (24-hour) days. First, we are told that He created the earth in darkness and then created light. Then He called the light "day" and He called the darkness "night." And then He said (in the original Hebrew) "and [there] was evening and [there] was morning, one day." He repeated the same statement at the end of the second day through the sixth day.
Everywhere else in the Old Testament, when the Hebrew word for "day" appears with "evening" or "morning" or is modified by a number (e.g., "sixth day" or "five days"), it always means a 24-hour day.
[Read the rest of the article at Answers in Genesis.]