When was the second Trunks created?

[Yukaphile]

We know there's four timelines in DBZ. In chronological order, this is what happened. In Timeline 1, Trunks traveled back in time to warn the Z Warriors about the androids, creating Timeline 2. Then he came back and Cell stole his timeline, creating Timeline 3 or the main timeline when he traveled back in time. Then comes the timeline Trunks forms when he goes back to the future and beats Cell, Timeline 4, the one Black Goku appeared. My only question is, when was Timeline 4 actually formed, and when did the Trunks from Timeline 1 change to the Trunks who created Timeline 4? I mean, logically, there should only be two places. Either when he traveled back into the new timeline Cell created and went back home, or after he helped the Z Warriors beat Cell. I know this is something of a brain-twisting question, but I'm genuinely curious what you guys think.

 

[The_real_cal_howard]

I think timeline 4 is actually timeline 2. T1 is the one when Cell kills Trunks, and 2 is the one with the Trunks we know and love. 3 is the one dead Trunks saved, and 4 is the main. T1 is the original, and created the rest. T2 due to Trunks, and the rest due to Cell's interference. This is just a theory though. An ANIME THEORY! Thanks for watching.