The topic of the sacred texts is "why people are so messed up and what God is doing about it". The topic is not "what physical processes did God use to create the universe and how long did it take".
Yes, the majority of the entirety of the Scriptures is about how messed up people are and what God is doing about it. But...
That isn't what all the 1,000 or so pages of writing, as we measure pages, is about. Pretty much all of the Pentateuch concerns historical narrative. Many biblical scholars believe that the first five books were written during the days of Moses and the Exodus out of Egypt. During that time, I believe through the Holy Spirit of God, just as Paul asserts, men were led by the Spirit to write down the oracles of God.
As to your claim that the topic in not "what physical processes God used", I am in complete agreement. As to your claim that it is not about "how long did it take", I am not. Three times in the whole of the Scriptures, God has the claim written down that He created all that is in 6 days. Now, I don't know what you consider to be an explanation of time, but 6 days is, to me, a length of time. Twice, God's word gives an accounting of years (another explanation of time) from one generation to the next. How anyone could have read the entirety of the Scriptures and not seen some explanations of time, is quite beyond me.
Now, does God's word go on for 37 paragraphs with pictures and drawings and equations to explain these passages of time? No!!! He just makes the claim that a certain amount of time passed during the creation event and He makes the claim of a certain amount of time passing from one generation to the next. They are very specific mentions of time and as for the six days, as I said, it is repeated at least twice more in God's accounting of historical facts.
Now, you are free to make the claim that God's word doesn't tell us how long it all took, but that would not be a true statement. I'm even smart enough to know that it isn't a true statement and it honestly throws serious doubt on your ability to be able to read and comprehend the things that God has told you. No one, with any understanding of language and communication, can honestly say that there is no explanation of time, as it passed in the beginning account of the Scriptures. They can say that the subject of the passing of the time described in the Scriptures is not what the gist of the Scriptures is about. But, they just can't say that there is no mention of time as it passed from the moment that God entered into this realm of His creating and the day in which we stand now some several thousand years later.
I know that God loves me and He wants me to understand just how important the choice I make in this life is. I know that He is impressing upon me that importance by assuring me that He did create all that is and the very fact that I have oxygen surrounding me to breath and continue my living on this earth is by His hand. That without Him there is no life. Not even for those who refuse Him His just place in their lives. After impressing me with that truth, He then wants me to know just how important it is one day, if not immediately today, that I choose to love Him who is the Creator of all things and who gives and sustains life. He wants me to be assured that none of this existence that I see around me came about by some 'natural' processes of the things that He made and that my future rests solely in His having mercy upon me because I have believed and trusted Him and repented of my sin.
God wants us to understand that none of this came about by any 'natural' processes. That just as the sea parted into a wide chasm because He commanded it to do so, despite all the 'natural' processes that would deny that a sea of water could do such a thing; that we also understand that none of the stars that we see in the night sky, and none of the physical properties of the earth came to be because of some 'natural' processes. God commanded, and things that were not...became!
God bless,
In Christ, ted