Natural theology is the view that science can not only be made compatible with various theologies (biblical or otherwise), but science - if 'properly' understood in context - can actually provide more information about the theology in question.
However, I would prefer to associate the first commenorative day with the creation of the universe, the big bang, rather than the formation of Earth, as it seems clear that life existed in the universe before it existed on earth.
I stayed focus on the planetary evolution of earth because I think it is closest to a Genesis parallel. However, I see a little self-similarity in the creation process itself. That is, I think the big bang and development of galaxies, etc, is very similar to planetary evolution, e.g., earth. Hence, as you suggest, Genesis could also be interpreted in light of the big bang, athough with the big bang you have to be talking more about 'potential' than the real thing.
In that case:
Day 1: The "let there be light" is release of the massive amounts of photons at the big bang which is the radiation dominant phase of the big bang. The end of the first day is by far the most amount of light ever emitted in one day in the history of the universe.
Day 2: The separation of the 'heavens' from the 'earth' could be several things. However, for fun, let's say it is nucleosynthesis (protons and neutrons binding), which is to say that the basis of 'matter' separated itself from the 'clouds' of elementary particles.
Day 3: Life in the universe became feasible. With the evolution of hydrogen, helium and lithium the evolution of suns became possible, thereby ensuring that life would evolve someday.
Day 4: Matter and radiation separate (CMB radiation), thereby the heavens of matter could now be 'seen'. The patches of galaxy clouds are already forming.
Day 5: Stellar evolution allowed for life to emerge in vast 'oceans of space' away from galactic clouds still experiencing heavy amounts of radiation that is fatal to life.
Day 6: Universe life evolves 'on land' in the galaxies themselves. Intelligence evolves thoughout the many 'lands' of the universe.
Day 7: God rests from creating the universe. With evolution complete God views a triumphant goal obtained. The Omega Point?