A few decades ago, the WT Society taught that the Great Tribulation started at the same time that the "last days" started (back in 1914) and would continue for the decades up until Armageddon. Then they moved the Great Tribulation to happen at the END of the last days.
For the longest time, the WT Society taugh that the "judging" of the nations into sheep and goats was ongoing through the last days, then around 1994 they moved that back to the END of the last days.
They also used to teach that Luke 21:28 about the nations being fearful but JW's lifting their heads erect was happening throughout the last days, but they've also moved that back to the END of the last days.
Not much happens in the "last days" anymore. (I guess they realized that.) Maybe most JW's don't even believe it's the "last days" anymore.