6 Days
He created the heavens and the earth in six days, and His Throne was upon the waters, to test who among you is best in deeds.
11:7And He it is Who created the heavens and the earth in six Days - and His Throne was upon the water - that He might try you, which of you is best in conduct. Yet if thou (O Muhammad) sayest: Lo! ye will be raised again after death! those who disbelieve will surely say: This is naught but mere magic.