Those two things are measured in school (absences and tardies). Showing up is half the work. “You’re late. But my watch shows that it’s just now 8am. Yes, but you weren’t here, so we had to use my watch.” “Ten minutes early is ten minutes late.”
Of course, there are times when it’s ok and maybe even expected to be casually late, like to a party. I know when we’re hosting Thanksgiving, I want people to arrive in time to eat, but it actually annoys me when they show up early because now I have to worry about entertaining them while trying to prepare the meal.