Exo 20:11 For in six days the Lord made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the Lord blessed the sabbath day, and hallowed it.
On the other hand, Jesus tells us that male and female were made at the "beginning" of creation, when Genesis 1 clearly puts them in day 6. And even Moses' writing in Genesis 2 shows us the creation of man, and then plants, and then woman, which would place the day 3 creation of plants firmly in the middle of day 6. This suggests that what is meant by "day" isn't what we're inclined to think of in our 21st century mindset.
Moses was adopted to Egyptian royalty, and wrote a creation account that subverts the Egyptian account. Reading the Torah without an Egyptian background is like watching West Side Story without knowing Romeo and Juliet, or watching Shrek without knowing Prince Charming. You'll miss all the references, or think their importance is for a different reason than it actually is.
Exo 20:11 For in six days the Lord made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the Lord blessed the sabbath day, and hallowed it.