Here is a comparison chart of the Creation Periods as explained in Genesis, Moses, Abraham, and from the LDS Perspective.
The LDS Perspective makes a lot of sense to my mind in 3 areas:
1. Grass grows only after day and night divided and sun, moon, and stars appear.
2. Separation of Light and Darkness/Day and Night emphasized over the creation of light and dark.
Light and Dark, like the materials used to form the Earth ,are eternal and have always existed.
3. Creation of man different day than creation of animals.
It is also significant that the creation of man is the only part of creation in which the Father personally participates by saying "Let us make man in our image". Putting the creation of man on its own day separate from the animals serves to further emphasize the divine origin of man.