Armageddon does not come and go, around the great tribulation.
It will seem like war is on every side, but there will not be war (there will be oppression).
Armageddon (har-megiddo) in Revelation 16:12-16 is a gathering location - i.e. a staging location about 80 miles north of Jerusalem.
12 And the sixth angel poured out his vial upon the great river Euphrates; and the water thereof was dried up, that the way of the kings of the east might be prepared.
13 And I saw three unclean spirits like frogs come out of the mouth of the dragon, and out of the mouth of the beast, and out of the mouth of the false prophet.
14 For they are the spirits of devils, working miracles, which go forth unto the kings of the earth and of the whole world, to gather them to the battle of that great day of God Almighty.
15 Behold, I come as a thief. Blessed is he that watcheth, and keepeth his garments, lest he walk naked, and they see his shame.
16 And he gathered them together into a place called in the Hebrew tongue Armageddon.
The he in that verse 16 is the sixth angel - due to his action of pouring out the sixth vial of God's wrath.
When his vial is poured out in verse 12, the Euphrates will be dried up making it easier for the kings of the east to proceed. In a prelude to Armageddon, the armies of the world converge to fight against the beast-king headquartered in Jerusalem, the battles of Daniel 11:40-44. As the fighting is going on, without warning like a thief in the night, the sign of the Son of man appears in heaven, Jesus sickle in hand.
That causes the fighting to stop, as fear grips the wicked of the world, knowing that their demise is at hand - the wrath of the Lamb has come in Revelation 6:12-17.
It then takes the convincing of the beast-king, the false prophet, and Satan in Revelation 16:13-14 that the kings of the earth should make war on Jesus to keep Him from executing judgment on them.
Matthew 24:
29 Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken: [the Revelation 6:12-17 event]
30 And then shall appear the sign of the Son of man in heaven [Revelation 6:16-17]: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory.
Between when the sign of the Son of man first appears in heaven - til the day Jesus descends to earth to the Mount of Olives in Zechariah 14:4 - is 45 days.
45 days based on Daniel 12:11-12.
1290 days from the day the abomination of desolation statue image is setup on the temple mount til the sign of the Son of the Man in heaven first appears.
And 1335 days from the day the abomination of desolation statue image is setup on the temple mount til Jesus coming in the clouds of heaven with power and great glory. Matthew 24:30b.
So, 1335 days - 1290 days = 45 days.
During that 45 days, the kings of the earth will assemble their armies at Armageddon. And also surround Jerusalem with their armies to take half of the city as hostages, Zechariah 14:2. All as part of their strategy to keep Jesus from executing judgement on them.
At the end of the 45 days, when Jesus does descend to earth, to the Mt of Olives, this happens....
