When does time become a factor when you are having a conversation?

Question

How long should you continue to talk after the other person stops and when do you say good bye?

In other words when there is a period of silence does this mean time is up?

Answer 1

The awkward silence means, "Oh I'm running out of minutes!"  or "Look at the time! I need to go!"

Answer 2

If you know the person is quiet and don't mind your talking then keep on, but the moment you ask something and they have no idea what you're talking about then it's bye-bye time.

It depends also, sometimes a silence can be real comfortable and enjoyable but the moment the silence is unbearable then time is up.