Is it possible that the universe could be eternal??...

[snowtracks]

How do you know that it is a summary of a long period of time as opposed to a literal account of a short one?  This is just shameless retconning.

Meh, I'd rather have them distort their religion to fit science than vice versa.

The Hebrew word translated “day” (Yom) in Genesis 1 has four distinct literal (yes literal) definitions: 
(1) part of the daylight hours, for example, noon to 3 PM; (2) all of the daylight hours; (3) one rotation period of Earth—currently 24 hours; and (4) an extended, but finite period of time.