Haha! It happened to me many times when I think about it now. I instinctively show my phone, even my watch, as I tell them the time. I've never stuttered so bad, so it seemed normal but incase I stutter and still want to have a normal interaction, I would detect it and not say anything at all and just show my watch or phone to them. That's better than showing my phone and stuttering after saying 4 and not being able to complete the thirty and force that person to stand there waiting even though they got what they asked for from seeing my phone.