[OneVike]

It would be useful to know the dialects employed and the cognates and nuances in use at the time before we can really determine the intent of the author.

I agree with your explanation of how it does matter when who and how it was written. That being said it still stands that the time was and still is considered one day by the Hebrew language and dialect, just as it does in today's analogy of the meaning.

The Hebrew word for day as I said earlier is yom or יום. And throughout the first five books of the Bible, Genesis, Exodus, Numbers, Leviticus, and Deuteronomy it has always meant what it implies. When yom is proceeded by a number as it does in Genesis 1:5

first day orיום אחד

יום would be the number one, or first

It means the number of days specified. In this case it means one day, as in the first day. Only when a number is not proceeding the word yom יום. does it mean an age of time.

I am short on time or I would give you an even more extensive lesson in Hebrew.

[Natural Law]

"The Hebrew word for day as I said earlier is yom...

You will also find that the ancient Hebrew measurement system, whether linear, volumetric, or time was almost exactly the same as the Babylonian system and that "day" did not mean a 24 hour period, it meant the time from the onset of darkness until the next onset of darkness. Since the ancient Hebrew language lacked the basic capability to describe non-linearities or abstract concepts like the space time continuum one can't take things too literally.