Come on time. And if someone stays late they should be paid for staying late 100% of the time.
But they also shouldn't have to stay late. People work jobs so they can afford life outside of work. Making people stay late is stealing from their life outside of work no matter how much they're paid.
When I was a retail manager, I was a hardass on people coming in so late that it would impact coworkers. I covered the floor in those situations, but I couldn't cover multiple departments, but when 3 people are out sick and 4 are late, I can't do it all.
I also fought corporate to authorize more hours so I could have coverage for people to get sick or stuck in traffic, but corporate were a bunch of assholes after our chief competition bought us out and slashed staffing.