Few things tend more to alienate friendship than a want of punctuality in our engagements. I have known the breach of a promise to dine or sup to break up more than one intimacy.

Small kept promises are most of what a friendship is made of. A canceled dinner seems minor because the stakes of one evening are low, but what it teaches the other person is that they are the thing that gets moved. Do that a few times and the friendship does not end in an argument. It thins out, and neither of you can say quite when.

Look at who you have rescheduled twice in a row. Go first, offer a time you will actually keep, and then keep it. Being reliably present matters more than being impressive once you arrive.