Arnie: Hello, I'm on my way to Warsaw. 
Betty: Hi, great!
Betty: What time do you arrive at the station?
Arnie: God knows. But theoretically 18:45. 
Betty: Do you want me to pick you up?
Arnie: That would be nice, but I doubt we'll be there on time.
Betty: True. 
Betty: Let's make a deal:
Betty: I'll come around 19:00 or 19:15. If you arrive on time, you'll wait in a cafe. And if you arrive later, I'll wait. 
Arnie: Deal!
Arnie is scheduled to arrive in Warsaw at 18:45. Betty will come to pick him up at 19 or 19:15.