The WatchTowerBTS says we're already in the last of the last of the last days, but that's not what the Bible shows...
Daniel chapter 2
"feet were partly of iron and partly of clay" (Daniel 2:33)
The UN is made up of NGOs and human groups as well as governmental authorities and representatives. The UN is the feet of iron and clay.
"And just as you saw the feet and the toes to be partly of clay of a potter and partly of iron, the kingdom will be divided, but some of the hardness of iron will be in it, just as you saw the iron mixed with soft clay. And as the toes of the feet were partly of iron and partly of clay, so the kingdom will be partly strong and partly fragile. Just as you saw iron mixed with soft clay, they will be mixed with the people; but they will not stick together, one to the other, just as iron does not mix with clay. “In the days of those kings the God of heaven will set up a kingdom that will never be destroyed. And this kingdom will not be passed on to any other people. It will crush and put an end to all these kingdoms, and it alone will stand forever, just as you saw that out of the mountain a stone was cut not by hands, and that it crushed the iron, the copper, the clay, the silver, and the gold. The Grand God has made known to the king what will happen in the future. The dream is true, and its interpretation is trustworthy." (Daniel 2:41-44)
The UN has not come to full ruling power yet. It will. We are not living in the end of the last days yet.
Daniel chapter 7
"After this I kept watching in the visions of the night, and I saw a fourth beast, fearsome and terrifying and unusually strong, and it had large iron teeth. It was devouring and crushing, and what was left it trampled down with its feet. It was different from all the other beasts that were prior to it, and it had ten horns. While I considered the horns, look! another horn, a small one, came up among them, and three of the first horns were plucked up from before it. And look! there were eyes like human eyes in this horn, and there was a mouth speaking arrogantly." (Daniel 7:7,8)
The small horn is the UN. It humiliated Germany, Austro-Hungary, and Germany.
"I kept watching as that horn made war on the holy ones, and it was prevailing against them, until the Ancient of Days came and judgment was rendered in favor of the holy ones of the Supreme One, and the appointed time arrived for the holy ones to take possession of the kingdom." (Daniel 7:21,22)
While the UN is ruling in its full power, it will attack and make war on the holy ones. Later during the great tribulation it will be the appointed time for the holy ones to take possession of the kingdom.
"As for the ten horns, ten kings will rise up out of that kingdom; and still another one will rise up after them, and he will be different from the first ones, and he will humiliate three kings. He will speak words against the Most High, and he will continually harass the holy ones of the Supreme One. He will intend to change times and law, and they will be given into his hand for a time, times, and half a time." (Daniel 7:24,25)
The UN starts as an extension of the US/UK but is different than the other previous kingdoms. The UN humiliated Germany, Austro-Hungary, and Italy after WWII with the settlements and treaties (those three kingdoms were previously under the domain of the Roman empire).
When soon ruling as the dominant world power, the UN will harass the holy ones of the Supreme One. It will be for "a time, times and half a time" or three and a half years.
Daniel chapter 8
"Out of one of them came another horn, a small one, and it grew very great toward the south and toward the east and toward the Decoration. It grew so great that it reached all the way to the army of the heavens, and it caused some of the army and some of the stars to fall to the earth, and it trampled them down. It exalted itself even against the Prince of the army, and from him the constant feature was taken away, and the established place of his sanctuary was thrown down. And an army was given over, together with the constant feature, because of transgression; and it kept throwing truth to the earth, and it acted and had success." (Daniel 8:9-12)
The UN is the small horn that grows great all the way toward the Decoration. The UN started as an extension of the US/UK. It will "cause some of the army and some of the stars to fall to the earth and trample them down" when it attacks all religions including Jehovah's Witnesses at the beginning of the great tribulation.
"And I heard a holy one speaking, and another holy one said to the one speaking: “How long will the vision of the constant feature and of the transgression causing desolation continue, to make both the holy place and the army things to trample on?” So he said to me: “Until 2,300 evenings and mornings; and the holy place will certainly be restored to its right condition.”" (Daniel 8:13,14)
Though the scriptures show the entire tribulation lasts 3 1/2 years, this verse shows there will be a refining in true worship. By the 1,150th day of the tribulation, Jesus will organize a refined people for God's name so that all the sheep can be gathered together there. (An evening and a morning equals one day. 1,150 evenings plus 1,150 mornings equals 2,300 evenings and mornings. 1,150 evenings plus 1,150 mornings equals 1,150 days.)
"Then he said: “Here I am causing you to know what will happen in the final part of the denunciation, because it is for the appointed time of the end." (Daniel 8:19)
The appointed time of the end hasn't started yet, but it will start soon.
"And in the final part of their kingdom, as the transgressors act to a completion, a fierce-looking king who understands ambiguous sayings will stand up. His power will become great, but not through his own power. He will bring ruin in an extraordinary way, and he will be successful and act effectively. He will bring mighty ones to ruin, also the people made up of the holy ones. And by his cunning he will use deception to succeed; and in his heart he will exalt himself; and during a time of security he will bring many to ruin. He will even stand up against the Prince of princes, but he will be broken without human hand." (Daniel 8:23-25)
The leader of the UN will be the "fierce-looking king who understands ambiguous sayings. His power will become great, but not through his own power. He will bring ruin in an extraordinary way, and he will be successful and act effectively" when he "brings mighty ones to ruin, also the people made up of the holy ones" when he attacks all religious institutions.
"What was said in the vision about the evenings and the mornings is true, but you must keep the vision secret, for it refers to a time many days from now." (Daniel 8:16)
All religious institutions will be attacked, but true worship will be refined by the 1,150th day of the tribulation.
"“How long will it be to the end of these marvelous things?” Then I heard the man clothed in linen, who was up above the waters of the stream, as he raised his right hand and his left hand to the heavens and swore by the One who is alive forever: “It will be for an appointed time, appointed times, and half a time. As soon as the dashing to pieces of the power of the holy people comes to an end, all these things will come to their finish.”" (Daniel 12:6,7)
The great tribulation begins when the UN comes to complete power. (Incidentally, that is when Jesus takes the throne in heaven and casts the Devil down to the earth.) It will last for 3 1/2 years, the appointed times of the nations.
"And from the time that the constant feature has been removed and the disgusting thing that causes desolation has been put in place, there will be 1,290 days. “Happy is the one who keeps in expectation and who arrives at the 1,335 days!" (Daniel 12:11,12)
There will also be specific noteworthy events at the 1,290the day and the 1,335th day. Revelation gives clues on these other events.
When Jesus talked about "Jerusalem being trampled for the appointed times of the nations" he is talking about the three and a half years of the tribulation when the UN is the dominant world power.