[DManA]

So for some observes, it could look like 4 billion years.

Those that suggest that the universe couldn't be created in 7 days just don't understand the nature of time; the passage of time, and it's measurement, is dependent upon the frame of reference of the observer.

[Technogeeb]

So for some observes, it could look like 4 billion years.

Quite easily; if an observer happened to be in the appropriate inertial frame of reference (none of which is any more, or less, "accurate" or "correct" than any other).