Meeting Start Times - Early, Late or Right on Time?

I appreciate that people want to start meetings on time.  I think it is important to respect all attendees times.  But one rarely discussed topic is whether it is ok to start a meeting early. I propose it is not. What if someone is coming from another meeting?  If you start your meeting early, you are saying that you are more important than the prior meeting/appointment.  It is important to respect everyone's time so an on time - no earlier or later is best. What is the best way to keep on time though? I struggle with this a lot. I submit every bell and whistle should go off on your desktop or smart phone (just remember to disable the phone when you get in the meeting). I also always try to plan for longer than you think. Meetings inevitably go over so I try to add 15 minutes lag time after each meeting so that you can wrap up and not be rushed to the next task without finishing the first one.