The individual days of creation are denoted by the phrase, “So the evening and the morning were the first day” (Gen. 1:5), “…second day” (Gen. 1:8), “…third day (Gen. 1:13), etc. All of this seems to call to mind a “day” as we know it. And when we study the other uses of the word in the Old Testament, we find that where the word yom is preceded by a numerical adjective (i.e. “first,” “second,” “third,” etc., as in Genesis 1), it always refers to a twenty-four hour day.