Does your reading of Genesis mean that you hold to a young earth or do you allow a sliding time scale similar to what Gerald Schroeder proposes?
Human history began on the Sixth Day of Creation with the creation of Adam. All history is dated from that event, and this is the 5771st year since that Sixth Day.
I am aware that some concordists like Schroeder try to reconcile uniformitarianism with Genesis, but my position is that this simply is not necessary. So why do it?