It's easy for us to get caught up in the details and miss the main message of all this. Yes, the Bible speaks of the moon turning to blood in Joel 2:31, Acts 2:20, and Revelation 6:12 but how does that apply to us in these "last days?" First, note that even Jesus had to deal with his disciples getting caught up in prophetic fervor but missing the real message of the moment. Read what He says to His disciples in Matthew 24.
Matthew 24:3-14 The Olivet Discourse
3 As He was sitting on the Mount of Olives, the disciples came to Him privately, saying, “Tell us, when will these things happen, and what will be the sign of Your coming, and of the end of the age?” 4 And Jesus answered and said to them, “See to it that no one misleads you. 5 For many will come in My name, saying, ‘I am the Christ,’ and will mislead many. 6 You will be hearing of wars and rumors of wars. See that you are not frightened, for those things must take place, but that is not yet the end. 7 For nation will rise against nation, and kingdom against kingdom, and in various places there will be famines and earthquakes. 8 But all these things are merely the beginning of birth pangs. 9 “Then they will deliver you to tribulation, and will kill you, and you will be hated by all nations because of My name. 10 At that time many will fall away and will betray one another and hate one another. 11 Many false prophets will arise and will mislead many. 12 Because lawlessness is increased, most people’s love will grow cold. 13 But the one who endures to the end, he will be saved. 14 This gospel of the kingdom shall be preached in the whole world as a testimony to all the nations, and then the end will come.
Now let me speak to the passage in Acts 2:14-31 which speaks of Joel's prophecy from Joel 2:28-32. Here's the passage so you can read it.
14 But Peter, taking his stand with the eleven, raised his voice and declared to them: “Men of Judea and all you who live in Jerusalem, let this be known to you and give heed to my words. 15 For these men are not drunk, as you suppose, for it is only the third hour of the day; 16 but this is what was spoken of through the prophet Joel:
17 And it shall be in the last days,’ God says, ‘That I will pour forth of My Spirit on all mankind; And your sons and your daughters shall prophesy, And your young men shall see visions, And your old men shall dream dreams; 18 Even on My bondslaves, both men and women, I will in those days pour forth of My Spirit And they shall prophesy. 19 ‘And I will grant wonders in the sky above And signs on the earth below, Blood, and fire, and vapor of smoke. 20 ‘The sun will be turned into darkness And the moon into blood, Before the great and glorious day of the Lord shall come. 21 ‘And it shall be that everyone who calls on the name of the Lord will be saved.’