Siki, I would most surely be wary of that
interpretation. Using "yaum" in the "period of time" sense and
hence as "stages" seems a more logical explanation for two
reasons.
Look at this:
http://www.lhup.edu/~dsimanek/cutting/ageuniv.htm
(maybe the people who plotted that are blind, but there isn't
enough data there and it doesn't show a curve, that shows a
steady increase to a sharp jump - but this is
irrelevant)
People have been arbitrarily (well, not so,
but in this sense, yes) declaring the age of the universe to
be some random number for millenia. Just because 3*4.5 = 13.5
does not mean the Quran means that.
I think you got
that from speed-light.info - I would take everything from
there with a pinch of salt.
The other, is that
supposing the Quran is indeed timeless, and we do not know the
time it is invalid - i.e. the day of judgement, we CANNOT say
that because 4.5 * 3 = 13.5, the verse refers to that
specifically. For all you know, we may survive for an
additional 10 billion years with ridiculously advanced
technology and an insatiable thirst for resources (i.e. alien
invasion!!!), and that definition would be completely
invalidated - (13,5 + 10)/(4.5 + 10) = 1.62. In other words,
absolute rubbish.