[Uncle Chip]

The missing element in our analysis is in failing to consider the entire chapter and how the apostles in the NT saw the fulfillment:

But this part that you cited was not fulfilled back in those days:

19 I will show wonders in heaven above And signs in the earth beneath: Blood and fire and vapor of smoke. 20 The sun shall be turned into darkness, And the moon into blood, Before the coming of the great and awesome day of the Lord. 21"

[topcat54]

But this part that you cited was not fulfilled back in those days:

Not according to Peter. I think the problem is that you are not approaching the prophecies in the same way that Peter and the other apostles did. If Peter did not believe that that those verses were being fulfilled in that day, the he might have stopped quoted from Joel at a more appropriate point. He did not. He was clearly not a "literalist" when it came to interpreting the OT prophecies. He saw them all as primarily being fulfilled in Christ's appearance and work back in those days.

It hard to get around the true meaning of Peter’s works unless you are willing to resort to a brute force disregard for what he was intending to say.