Early for me...I'm already a "15 minute early" person, so what's another 5 minutes. The only things I'm not early for are when people are having a gathering at their homes. Showing up before the time they tell you is rude, especially if they are using that time to get all the little things ready.
Early. Our admin asst at work was constantly late to work in the morning, late coming back after lunch. Several of us would plan to have dinner; she was always late. Always. People who are always late are discourteous. It is always more about them than about others. Selfish. We stopped inviting her.
I don't mind being 10 minutes early but 20 minutes is kind of a lot. However, I don't like to be late either. I have a friend who I adore but she is constantly late when we meet for lunch. She always has an excuse but not really a valid one.