This is something my T is very skilled with. I don't recall her ever saying "time's up." She seems to know how to steer the conversation to a conclusion and usually starts making comments about what my goals for the next few weeks should be.

I'm also very conscious of the time, so I make an effort to wrap up what I'm saying too. But I do notice that she is very good at directing a conversation in a particular direction. That probably sounds manipulative but I don't think she tries to manipulate our sessions for her benefit or anything!