So...how many years is each day of six days?
In the beginning, YHVH created the Heavens and the Earth.....and so on and so on.
Before THE Man (Adam) was created, there were unknown periods of time. Ha Adam, is not just Man, but The Man, the progenitor from which the Messiah would come.
Cain went to Nod, and built a life there. So there were other humans on Earth. From the OT through the NT into today, the Books are the story about the Race of man that came to us from Adam.
My belief has room for what we call Dinosaurs walking with humans, an Earth without ice continents etc.
I don’t know, and hope someday to know. Until then, I am enjoying my time here to the best of my ability.