Showing up on time isn’t about the clock. It’s telling people their time is real to you.

Punctuality looks like an administrative virtue and works as a message. Being somewhere when you said you would be says that an hour of another person’s life is as real to you as an hour of your own, and being reliably late says the reverse without ever putting it into words. Nobody is counting minutes. Everybody is reading the pattern.

Build in ten extra minutes instead of trusting the best-case trip, since that is where most lateness actually comes from. Plan to arrive early and bring something to do while you wait. If you are going to be late, send the message before you are late rather than after.