The creation account in Genesis 1 says that on the fourth day God made the sun, the moon and the stars. The stars... how much of the universe did God make on day four? All of it?
So many questions come out of what happened on day four - stars 100's of light years away. Were they created 6,000 years ago? Is this why light had to be made before anything else?
We are also told here that these things were put in place to mark time - days and years. We would not get our week until creation had finished after the 7th day.