Just a random thinking outside the box thought I had today. It began with doing a little more reading about space/time.
Scientifically, it's known that as one approaches the speed of light, time slows down for them.
Just to be sure Cofty won't cry about not reading a 'basic' book vs credible internet resources, I'll quote from a 'basic' book, "String Theory for Dummies" http://www.dummies.com/how-to/content/slowing-time-to-a-standstill-with-relativity.html
Here is a small example to explain how for what could be seconds for a person ends up being thousands of years for those on Earth...
"""One other case where time slows down, this time in general relativity, involves black holes. Recall that a black hole bends space-time itself, to the point where even light can’t escape. This bending of space-time means that as you approach a black hole, time will slow down for you relative to the outside world.
If you were approaching the black hole and your best friend Dean was far away watching (and could somehow watch “instantly,” without worrying about the time lag from light speed), Dean would see you approach the black hole, slow down and eventually come to rest to hover outside of it. Through the window of your spaceship, Dean would see you sitting absolutely still.
You, on the other hand, would not notice anything in particular — at least until the intense gravity of the black hole killed you. But until then, it certainly wouldn’t “feel” like time was moving differently. You’d have no idea that as you glide past the black hole’s event horizon (which you possibly wouldn’t even notice), thousands of years were passing outside of the black hole."""
If a human was moving at close to the speed of light or could hit it, would not 1 day for them would equal thousands, millions, billions of years?
So whether the bible is talking about 6 human standpoint days or 6 symbolic days, if it was 6 literal days from our standpoint if a human was moving at those speeds it would be 6 days for them but untold number of years on Earth, same principle would apply to God.