well, like I said, it's a rabbit hole and I get beyond my ability to articulate it pretty quick ... but the question simply serves as a point about which to consider whether we can know God created the universe in 6 calendar days or not.
The six days pretain to earth and the earth week with the seventh day, Genesis 1:3-31, Genesis 2:1-4, Exodus 20:11.
I agree about the six days for reestablishing the boundaries of the water and placing the life forms with their habitats in place.
It is evident in Genesis that God did not have to call into existence the water and dirt, they were already in place. That in no way brings the six day creation into question, but does explain why science is wrong when they look at the age of the planet, and think it was always the way it is.
The planet as it is dates about 6 millennium.