The Iron - 57:4
He it is Who created the heavens and the earth in six days and then established all authority. He knows everything that enters the earth and comes out of it, and everything that descends from the sky and ascends to it. He is with you wherever you are. Allah is the All-Seeing of all that you do.
Six days is unit time:
Explained in Detail/41:9
"Say, "Do you disbelieve in Him Who created the earth in two days and do you associate partners with Him? He is the Lord of the universes."
Explained in Detail/41:10
He placed on it elements of balance and made it fruitful, and measured and arranged its food in four days for all who seek.
Explained in Detail/41:11
"Then He turned to the smoking sky and said to it and to the earth, "Come (out of chaos) willingly or unwillingly". They said, "We have come willingly."
Explained in Detail/41:12
So He completed them in two days as seven heavens and revealed to each heaven its special laws. And We equipped the lowest heaven with lamps and a system of protection. This is the plan of the Supreme and All-Knowing.