Before we begin, please read the article about the word “yom”. This is one of the Hebrew words for “day,” and it was the word used during the Creation week in Genesis Chapter 1. If you read through each day of the creation week, you will see that there are qualifying words to help determine the meaning of “yom.” For example, on the second day of creation, the text reads: “And there was evening and there was morning, the second day” (Gen 1:8). So when you have the word “day” accompanied by “evening,” “morning,” and an ordinal number (second), then this commands that the word mean a literal 24-hour period, just like we have today.
The word “day” occurs 2,031 times in the Old Testament, but why is it only questioned in Genesis? Was Jonah in the great fish for 3 days or 3 thousand years? Did Joshua march around Jericho for 7 days or 7,000 years?