In that conversation, they were talking about anywhere from 100-300 years. Not exactly an exact science. ;)
The term used was "technodelic utopia".
I think you'll enjoy this conversation:
http://thirdeyedrops.com/mind-meld-58-microdosing-future-michael-garfield/
The part I'm referencing starts around the 48-minute mark, but the whole thing is worthwhile. Lots of great philosophical tangents with these two guys.