Board Thread:Versus Debates/@comment-27233105-20160130092635/@comment-9782468-20160203051903

@Rachin, Itachi is in control of the victim's perception of time, so I think that particular use was 72 hours.

@MIGshinobi, I understand the world still goes by normal speed. But Kakashi is suddenly thrust into a world where there is 72 hours. So if he got out of Tsukuyomi before Tsukuyomi was technically over, he'd be out in less than a second.

The reason this is possible is because the Genjutsu doesn't only last a second for Kakashi. He himself is experiencing 72 hours. So that's the amount of time HE has in a second. One could get out of Genjutsu in that time if they were powerful enough. The whole reason a Jinjuuriki isn't immune to Tsukuyomi is because only the user is affected; the Bijuu wouldn't shake them out in time. But the victim has more perceived time with which to get out. Itachi sped up their perception in casting Tsukuyomi.