User blog comment:Xilinoc/Ch. 605 - Don't Call My Name/@comment-5693502-20141113174043/@comment-5398287-20141115062142

I'm fairly certain that the whole "distorted my sense of time" was sort of a literal translation of something more like "made me lose track of time". It's entirely possible that Aizen just made enough small talk with him that Yhwach lost track of what time it was, and honestly, I feel like that's more accurate to his original character than simply fusing with his Zanpakuto to gain constant access to its power.