The claim that the word “day” means only a measurement of time is not an accurate claim. The Hebrew word used is yom, and it is used just as our English word, day, is used. We use the word day as opposed to night, in the sense of “daytime;” we use the word day to mean a full 24-hour period, consisting of one period of daylight and one period of nighttime; and, we use the word day to indicate an age or era, such as, “in the day of the Roman Empire,” or, “back in my father’s day,” etc. Even though we use the word day for all of these uses, we are never confused as to which meaning is intended — why is that?
Note this vital fact: anytime that a number is used with “day,” whether in English or in Hebrew, a literal day is meant. Look outside of the disputed chapter of Genesis 1, and you will find that the Old Testament uses yom together with a number 359 times, and every single use is undeniably a literal day*. This only makes sense — just look at the English: If I say, “back in my father’s day,” we all understand it to be figurative of an age; but if I say, “in my father’s third day,” you would immediately want to know, “Third day of what — third day of existence?”
There is no ambiguity in how these words are used or what their meaning is. Rather, those who desperately want to find a way around the stark reality of what the first chapter of Genesis indicates have simply grasped at this straw and now feed it to those who don’t know better as if they can’t rely on the meaning of “day.”
Stand firmly on the Word!