Hi Mike! And here I am at 4:50 Am my time!
Before we get to the meat of what you're asking, we need to cover the basics of your interpretation of Scripture. You're asking for "Biblical" reasons, so we must start there! You take the "Traditional" view, which I did for many years. A change had to occur in my understanding of what Genesis was before I could understand the arguments here. I was gone from the Forum here for 31/2 years as I was not then prepared to embrace this interpretation fully, and now only recently returned.
The first object is "what is the meaning of day in Genesis chapter 1.
If you are accepting Genesis 1 is a factual accounting of a material creation, then you are limited to that interpretation. The only way to go beyond that is to see that the "Original Text" written by the originally inspired author (through Holy Spirit) was written To ancient Israelites (or verbally passed by storytelling narrative until written by Moses) However, it was written FOR us in all ages since then.
As John Walton explains in both his "Lost World" books, the Genesis account is an Ancient Near-Eastern document. Written to them. It has all the language, idioms, word plays, and narrative cues common to a verbal society in ancient times.
If I was to say to you, "in the day of Richard Nixon" what does that mean? A 24 hour day? Of course not. It means a period of time relating to the years of his terms of office and the Watergate scandal. The usage of the word day (and week) is a functional word concerning the ANE's common usage of a time period where some kind of relationship was established between a person (mankind) and the world around him. The usage of days and weeks is a common storytelling narrative "structure" used to place the ideas firmly in the minds of the listeners. As a child did your ever recite sing-song the ABC's as "A, B, C, D, E, F, G, tell me what you think of me!" and get a reply from gramma "Oh what a good boy you are!." That's the kind of thing verbal cultures do!
Walton's work is based on the translations of hundreds of pieces of ANE creation texts from the surrounding cultures. Only now with the aid of digital processing, the hundreds of clay tablets mouldering away in archeological storage have been translated and now available. From those we see that the Genesis account is both very similar, yet has some very important distinctive differences. While the narrative structure of the account is similar, and common to the era, it also does not include a war in the deeps of pre-creative time, the enslavement of humans to do the work of the gods, the corrupt human-like attributes of the gods, the use of blood, mud and semen, and so forth as the creative material.
In prior generations the inspired scripture, and Biblical scholars were working from within their own cultural understanding, they wrote and thought according to their cosmology (how things in the cosmos work). God allowed his scripture to be passed down in that manner. The earth was a disk with a solid sky held up by pillars. Somebody posted a picture of traditional ancient Hebrew cosmology on one of the topics. I can't find it right now).
There was nothing wrong with that, it is the way the world works.
The problem is that we, all of us who live in these times think in a material How manner. It is inbred into us from everything we see, feel, and learn. We know the earth is round, we know what gravity is, we know that there is space and planets, and that the earth appears old just by looking at a road cut.
and all of us "know" a Genesis day was 24 hours because the Bible says so.
So to not prolong what you have already read on this forum, think about this before we engage in further discussion on the relative age of the earth versus scripture. If you can't wrap your head around an ANE Genesis, then you will not get there by arguing the science against scripture as you know it.
Please take this from somebody who has been reading your questions ever since I came to the Forum. And read my prayer I just posted at My Prayer