I believe the angels were made before Creation week, as he made man after "our image":
26 Then God said, "Let us make man in our image, in our likeness, and let them rule over the fish of the sea and the birds of the air, over the livestock, over all the earth, and over all the creatures that move along the ground." (Gen. 1:26)
And the LORD God said, "The man has now become like one of us, knowing good and evil. (Gen. 3:22)
and then, of course, Satan's right there, "craftier than any of the wild animals" God had made:'
1 Now the serpent was more crafty than any of the wild animals the LORD God had made. He said to the woman, "Did God really say, 'You must not eat from any tree in the garden'?" (Gen. 3:1)
Plus, he posted an angel to guard Eden after expelling Adam and Eve:
24 After he drove the man out, he placed on the east side of the Garden of Eden cherubim and a flaming sword flashing back and forth to guard the way to the tree of life. (Gen. 3:24)
All this without mentioning the creation of angels!
Perhaps He had already created such things as angels, and Satan had already fallen from pride, before the creation of Earth, and simply did not make it included in the Bible. I'm sure there is some reason to this; it was irrelevant and would only encourage an obssession with something supernatural other than God; it simply had nothing to do with man, I don't know. Maybe we only needed an account to start from the creation of our world (and possibly dimension, I'm confusing myself) and there was about as much possibility of describing the creation of angels as there is of explaining color to a blind man.
1 Thus the heavens and the earth were completed in all their vast array.
2 By the seventh day God had finished the work he had been doing; so on the seventh day he rested from all his work. 3 And God blessed the seventh day and made it holy, because on it he rested from all the work of creating that he had done. 4 This is the account of the heavens and the earth when they were created.
(Gen. 2:1-4)
That's it. It's an account of the heavens and the earth when THEY were created. Not necessarily anything besides the heavens and the earth. But how would I know? You'd do best to ask some more researched person....