punctuality is one characteristic of successful people. are you usually on time for your appointments?
when you are on time for a meeting, you show that you care about the person you are meeting with. you show your respect for the other person's time. when you are late for an appointment, you are saying by your actions that your time is more valuable than the other person's.
being punctual tells something else about your character. it says, "i'm a person of my word." when you promise to be somewhere at a certain time, your effort to be there is a sign that you keep your promises.
on the other hand, if you are conducting a meeting, remember to start it on time, regardless of who is present. this is a sign of respect for those that have arrived on time.