 Outside of the actual future tenses, we can talk about things in the future, but use present tenses. Two of them are, present simple and present continuous. We use the present simple typically to talk about timetables and schedules. I'll say a statement such as, the train leaves at 6pm. We could also use present continuous when talking about future arrangements. I've arranged something in the future, so I could say something like, we're playing football on Saturday. It's been arranged.