When were the angels created? It was a question of some moment for the rabbinic interpreters, and for the Church Fathers - I seem to remember a lengthy disquisition in The City of God on the topic. I had some new light on the question recently in Dr. Barker's Temple Theology (2004). The rabbinic interpreters were very insistent that the angels were not created on the first day, but there is (possibly) good reason to believe that an older tradition held that they were.
If each part of the Temple was a pattern of Creation, then the Holy of Holies was the First Day, over which the firmament of the veil was stretched out. Within was the Unity, beyond time and matter, and it was also the abode of the angels - as the ideas or laws or even the elemental forces of creation. The clues are there in the songs and hymns of creation, in the Song of the Three Hebrew Children, and in Psalm 148: the angels are mentioned with the heavens, before all other beings, before even the "waters above the heavens" which were separated from the "waters below" on the Second Day in the creation of the firmament, and before creation of the stars.
There is also (and the rabbinic commentators agree on this) an idea of timelessness about the first day. In the particularly pregnant ordering of Genesis 1, the "evening and the morning were the first day". Considering that the light was created on the first day, that means that the primal darkness was God's first work, the hovering Spirit's nest. In that Holy Place the angels were hatched out from God's decree and order and in some sense are the Form of the divine pattern.
One is tempted to ask - did Jeremiah meet Plato after all?
I have often found a philosophical difficulty with talking about things, even qualities of things. Perhaps this is my own difficulty, and does not really exist. But the problem is this: that things, objects, seem to dissolve before analysis, and are crying out for some idea like Plato's Forms to guarantee their permanence as ideas. The content of the ideas sometimes bears little relation to the phenomena of the things themselves: lions are not especially brave, we are told by the expert observers. Nevertheless, the complex ideas related to these Archetypes have a relentless power and permanence over not just an individual but a collective imagination.
I do not for a minute believe that this fact can be explained away by reductive explanations of human consciousness. Metaphysics needs Forms, although perhaps they should be called angels by Christians, Jews and Moslems. I have been reading bits of the Victorines of the twelfth century, especially Thomas Gallus, who provides a detailed analysis of the moral life and the virtues, where each of the nine angelic hierarchies is a rung of the ladder of man's being as it aspires toward God, culminating in the highest two orders: the cherubim (representing for Gallus the knowledge of love, attained through contemplation) and seraphim (the divinely communicated spark of Love itself, kindling the soul beyond all knowledge and telling). I am amusing myself at the moment by trying to cross-reference Gallus with Dionysius and other sources and to come up with a angel hierarchy of external, visible creation. The game is that each of the nine orders must follow Gallus' outline, but their idea must be manifested in some way to our senses. Coming soon...
Here is a link to Part 2, and also to Part 3.