God works outside of time.[/quote[
Correct. God is not restrained by the passage of time that He created for us.
His days are like a thousand years and a thousand years are like a day.
Peter was trying to tell people (who wondered WHY things just keep going on like before when salvation was supposed to be imminent) to be patient. He was reminding them that God is outside of time, and so what might seem like a very long time to us won't seem like that to God. Of course God doesn't experience "days" at all (24 hour days or thousand year days) because, as you've pointed out, God works outside of time. But He created days for us, and knows how WE experience them.
I imagine that, as I write this, God can be "living" the creation of the earth, the flood, the exodus, and the birth of Christ simultaneously.
God bless