It's not a matter of questioning Genesis's truth, it's a matter of questioning its...well, I can't think of the word. But, for example, if I were to say,
My pet, Gracie, is a mammal.
That would be a true statement. But there are thousands of species that are classified as mammals, so telling you that Gracie is a mammal is not very descriptive, now is it?
It's the same with Genesis. It is 100% true, but is it descriptive? Hardly. The word "day" could mean any amount of time,
For a thousand years in your sight
are like a day that has just gone by,
or like a watch in the night.
To quote Psalms 90:4.
Hmm, I feel like I've had this discussion before.
Real science backs up Genesis 100%!
Define "real science." Most National Geographic articles and other scientific journals state that the earth is billions of years old, which you obviously disagree with. You could respond by saying, "Well that isn't real science!" So then is real science defined by what you believe to be true, and all evidence to the contrary is discarded?
If that's what everyone took "real science" to be, then we'd still believe that the sun revolved around the earth, and that it was flat. That was accepted fact for many years. But science has since shed new light on the subject. In fact, those who stated that the earth revolved around the sun were branded "heretics" because many people of faith stated that the Bible supports a geocentric solar system with a flat earth. It was a misinterpretation, most people of this day and age would say, but then again, that's what I'm saying about a literal six-day creation.
If I may quote Mystery Science Theater 3000...
"Fine! I admit the superiority of your unprovable theory over my unprovable theory!"