There is movement of change (approaching act) and movement of operation (which can only happen when in act).
Perfect act for God is not “rest” without movement, but “enjoyment in perfect operation” of his act, thus the Father is eternally in the operation of generation of the Son, the Son eternally in the operation of loving the Father and eternally knowing and saying “This is my Body, given for you”, the Holy Spirit eternally proceeding.
Now, this eternal knowing, saying, proceeding is not “now”, as an “eternal now”. It is totally singular and simple knowing, once. The “once” is eternal. That is how we can be with Jesus and the 12 at the last supper, because Jesus is knowing it “once”, and we are participating in his knowing. That is also how Peter, James and John could see Moses and Elijah and the radiant Jesus on the mountain, the real Moses and Elijah (who climbed the mountain in their own times), not “resurrected Moses and Elijah”. All on that Mountain were seeing as God sees at that event, which is knowing all in one singular knowing. They were outside of time; you are outside of time at the Eucharist when you see the Body and Blood of Christ at the Altar.