Rather than thinking of creation as being accomplished in 6 days, consider viewing creation as taking place in two sets of 3 days each.  In this view of Creation for the first 3 days God creates time, space, and life and in the next 3 days, to govern or rule the first 3 days, God fills the first 3 days with heavenly lights; fish and birds, and beasts and man.

CREATES REHLMS	FILLS WITH RULERS
TIME [light from darkness] Genesis 1: 3-5	SUN, MOON, STARS, PLANETS Genesis 1: 14-19
SPACE [heaven and the seas] Genesis 1: 6-10	FISH, BIRDS Genesis 1: 20-23
LAND/ LIFE [dry land and vegetation] Genesis 1: 11-13	BEASTS AND MAN Genesis 1: 24-31

[this view of Creation is known as the "framework hypothesis"]