I will admit that people running late is one of my pet peeves; to me it says that I wasn’t worth being on time for. I realise that some things are out of your control, but there are a lot of people who never leave any extra time for anything. I hate to break it to you, but that’s just life! Sometimes you will need to plan for a few extra minutes and that’s just the reality of it!
I believe that life is full of impressions; even if you have met someone a thousand times, you are still making an impression on them. Being late once? That’s life. Being late on a continual basis because of traffic, weather, a broken elevator, a slow barista, or a number of other things? That gives the impression that you don’t know how to manage your time to arrive when you need to.
There are some people that I have known for years that I won’t make plans with based solely on the fact that they are always late, and I don’t need to waste my time. When giving agreeing to give references, punctuality and time management play a huge part and I will often decline to give one if it is clear that you can’t be on time. (Decline to the applicant themselves, do not give a bad recommendation as it may be considered slander in some countries!)
Being on time is a very simple thing that goes a long way to showing the people around you that you are responsible and considerate, and being on time will never send the wrong message! The occasional late arrival happens to all of us, but a pattern indicates a bigger issue.