Board Thread:General Discussion/@comment-4115054-20140903063305/@comment-5398287-20140903072035

That whole thing about Aizen disrupting his sense of time was a translation error. Basically, Aizen caused him to lose track of time through small talk or something - he didn't outright affect his ability to perceive time.

Also, I'm not sure that Complete Hypnosis allows Aizen to make his victims think more or less time has passed, and if he still had access to it, he wouldn't currently be imprisoned. That, and the fact that Yhwach would've had to have seen him release Kyoka Suigetsu for the hypnosis to affect him in the first place.