So here's the crux of the matter: to you the universe formed "naturally." This is because you are a uniformitarian who believes that scientists, by looking at the world that exists today, are seeing the same processes that brought it into existence in the first place. This reduces Genesis to "theological truths" and historical and scientific error.
The creation of the universe began with Yehi 'or (that's fiat lux to you) and concluded with the creation of Adam and Eve on the Sixth Day. Until the universe was fully formed and created at the end of those six days the laws of nature as we know them did not exist. As I have stated numerous times on this forum the original human gestation period was a matter of moments, and Adam and Eve brought forth their first five children with two acts of copulation on that Sixth Day (the human gestation period was lengthened to nine months as a punishment for the sin).
The world as it originally slipped from G-d's hands is beyond the purview of science, and all the more so the coming-into-being of that world. Your stubborn insistence on turning the supernatural formation of the universe into a natural phenomenon is uncalled for, but expected.
Have you a reply regarding the length of each day?
Sure. Each "evening" was twelve hours and each "morning" was twelve hours. You know what an "hour" is, right? Probably not. An "hour" is by definition "one twelfth of a day/night" (the absolute hour we know today is a medieval Arabic invention). In the winter daytime hours are short and nighttime hours are long. In the summer the opposite is the case.
But you're missing the point. You want to define "day" as zillions and zillions of years so you can believe the universe formed "naturally," when "nature" properly speaking didn't even exist until after the six days.
Mindreading?
That's not permitted on the Religion forum.