One thing is for sure, it occurs the same day the Lord appears according to the scriptures I posted.
Now as to the times and the epochs, brethren, you have no need of anything to be written to you. 2 For you yourselves know full well that the day of the Lord will come just like a thief in the night. 3 While they are saying, “Peace and safety!” then destruction will come upon them suddenly like labor pains upon a woman with child, and they will not escape. 4 But you, brethren, are not in darkness, that the day would overtake you like a thief; 5 for you are all sons of light and sons of day. We are not of night nor of darkness; 6 so then let us not sleep as others do, but let us be alert and sober. 7 For those who sleep do their sleeping at night, and those who get drunk get drunk at night. 8 But since we are of the day, let us be sober, having put on the breastplate of faith and love, and as a helmet, the hope of salvation. 9 For God has not destined us for wrath, but for obtaining salvation through our Lord Jesus Christ, 10 who died for us, so that whether we are awake or asleep, we will live together with Him. 11 Therefore encourage one another and build up one another, just as you also are doing.
6 For after all it is only just for God to repay with affliction those who afflict you, 7 and to give relief to you who are afflicted and to us as well when the Lord Jesus will be revealed from heaven with His mighty angels in flaming fire, 8 dealing out retribution to those who do not know God and to those who do not obey the gospel of our Lord Jesus. 9 These will pay the penalty of eternal destruction, away from the presence of the Lord and from the glory of His power, 10 when He comes to be glorified in His saints on that day, and to be marveled at among all who have believed—for our testimony to you was believed
[Apparently, some Amils must think that the GWTJ also occurs and finishes during this same twinkling of an eye? ]
The GWT is all about sudden and eternal destruction away from the coming presence of the Lord.
How long do you propose it is going to take?