A: What time does your plane leave?
B: It leaves at 12:15.
A: When do you have to be at the airport?
B: I have to be there two hours early.
A: So we have to be at the airport at 10:15.
B: That means we have to leave the house at 9:15.
A: Well, it's an hour to get there, if there are no traffic problems.
B: So maybe we'd better leave at 8:15?
A: Yes, it's better to get there too early than too late.
B: I agree.
A: You never know what might happen on these freeways.
B: There's at least one huge accident every day.