Everyone knows showing up more than a few minutes late is considered rude, but what about the opposite?

Depending on how close you are with the friend in question, it might not be a big deal — some people have exceedingly casual dynamics, and arriving a bit early could allow you to help them as they finish setting up. It could also be uncomfortable, however, especially if they aren’t fully ready themselves and were counting on a few extra minutes to finish putting themselves together. Maybe it’s best for the early birds to wait in the car until the exact start time to avoid any potential awkwardness.