Trying to pin the Bible down to specifics when it is obviously being poetic (morning and evening of a “day” without a Sun), and then insisting that reality be viewed through the prism of this literal interpretation; is just warmed over gnosticism.
Sorry, but the bible is not being poetic in Genesis 1 & 2. It is being descriptive.
The perspective of God does not mean poetic (although He is the ultimate of all poetry.)
The perspective of God is from a dimension many don’t acknowledge, although it is the ultimate REALITY, “for God is Spirit, and those who worship Him must worship Him in Spirit and in Truth.”
Therefore the perspective of the Great Author is the critical issue. For the Timeless One to assert that it is a day is to invite us to view that statement from His reality, and He is the one unbound by time. Therefore, to say that “a day with the Lord = 1000 years” is to forget that God is not bound by linear time. He is the Alpha AND the Omega, the beginning AND the end.
Thus, God knew both the presence and the absence of the Sun at the same time. He could easily accomodate the length of an event and measure it relative to the time of our dimension.
The best explanation of the facts is that the duration He addresses (a day) relates to the REALITY He had just created. Perhaps a proportion or a quantity, but it is NOT some will-o-the-wisp of fancy with no basis in fact.