As a person who tends to be precise and literal, I would find these early people who scold others very annoying.
Many years ago I had a friend who was always earlier that the time she said she would be. Although she was very pleasant about it, I felt strange to do my final preparations with her waiting. After a few instances of this, when she would tell me the time she was coming. I started saying something like........
Now is this "Cathytime" that you are telling me, or is it Eastern Standard Time. She *got it* right away, and the problem was solved.