The way I understand the WT’s interpretation is that the “Great Tribulation” is really referring to a complete package of items to occur right after the sufficient fulfillment of the nations ‘crying peace and security,’ beginning with the destruction of Babylon the Great by the seven-headed, ten-horned wild beast and the apparent “celestial phenomenon” to immediately follow (whether symbolic, literal, or both), and ending with the actual Armageddon. According to this, you could think of the “Great Tribulation” as being like a giant .ZIP or .RAR archive file which gets “unpacked” at that point immediately after the “peace and security” proclamation thing when Babylon the Great is about to be turned on, which then presents all the individual items, like the individual, “uncompressed” files which together formed the composite “zipped” archive file.
In other words, the big .ZIP or .RAR self-extracting archive file is just waiting to be double-clicked by Jehovah, unpacking what is referred to by Jesus as being “all these things” when he said at Matthew 24:34: “Truly I say to you that this generation will by no means pass away until all these things happen.” (RNWT)
Jesus said in verse 21, “. . . for then there will be great tribulation such as has not occurred since the world’s beginning until now.” Then in verses 29 and 30, he said, “Immediately after the tribulation of those days, the sun will be darkened, and the moon will not give its light, and the stars will fall from heaven, and the powers of the heavens will be shaken. Then the sign of the Son of man will appear in heaven, and all the tribes of the earth will beat themselves in grief, and they will see the Son of man coming on the clouds of heaven with power and great glory.”
Regarding the quote by “leaving_quietly” mentioned above, “So, the tribulation does not culminate in Armageddon, according to Jesus. Right AFTER the tribulation, is when signs in heaven will be and when the "second coming" occurs,” that could not be correct. A correct rendering of that would read: “Right AFTER that specific part of the tribulation, . . .”; i.e., right after that initial phase of the Great Tribulation when Babyon the Great is to be turned on. The Great Tribulation refers to the whole thing – including Armageddon as the very last part of it.