Hi:
Contrary to popular belief Light was not the first thing God created:
"...
and the Spirit of God moved upon the face of the waters, Gen. 1:2b.
Water was the first thing which God Created - unless you want to say that water is as eternal as God? I hope not.
I think that the water referred to here are the waters of the Earth from which the land rises up, 1:10. Thus, the perspective of the whole Creation week is from that of Earth.
When God created light - it was an external light source shining upon the waters. From the perspective of the Earth a twenty-four hour day should be expected.
What I find very compelling is Dr. Humphrey's "White Hole Cosmology" from the Answers in Genesis:
http://www.answersingenesis.org/home..._cosmology.pdf
Blessings,
-CH