If they are upset, explain your reasoning in telling them the earlier time. Tell them that this event was time sensitive and you were afraid they would be late.
Say “When you’re late for these events, it’s really frustrating for me. When we go to the movies or to a show, we never get to see the whole thing and that’s unfair. Can you work on being on time in the future?”
For instance, you might allow them to come in late and stay later, as well. Give them a two week limit on this type of schedule so that other employees do not get jealous.
With friends, you might refuse to go with them to time sensitive events like concerts or movies.
Give your friend an earlier start time than everyone else. For example, if you are having a party, then you could give your friend a special invitation that specifies a start time 15 to 30 minutes earlier than everyone else’s invitation. Avoid inviting your friend to time sensitive events. Stick to activities where time is not an issue. Don’t do anything. Another option is to simply let your friend be late and allow them to deal with the consequences of that. For example, if you have a dinner party and your friend arrives late, then the might be naturally embarrassed if everyone is already there and halfway through the meal.
If they are your employee, then it might be time to fire them.
