[27/m] dating [22/f] concerns with her poor time management

I've been dating her for one year. We met in college and live 2 hours apart now that I've graduated. Things are going great, but we tend to get into arguments over her tardiness. She is this way with her friends/family as well.

For instance, if we had dinner reservations and the plan was for her to come over to my place at 4 pm, she wouldn't get here until 7. There's been many instances where shes been as late as midnight to 2 am. She comes every 2 weeks, and for the last 4 months I think shes been on time maybe once. We had numerous talks about this, and it's gotten as far as almost breaking up, because I would get frustrated.

Oh, today is our one year anniversary. She was supposed to get her at 1 pm, since I had reservations. Turns out she wont arrive until 7-8pm.

TL;DR: Girlfriend is always late for things. Today is our one year and she will also be late for that.