Why won’t Mr. Stone come to the clinic tomorrow?

W: Clinic. Can I help you?
M: Good afternoon. This is Frank Stone. I want to make an appointment with Doctor Milton, please.
W: OK, Mr. Stone. We have you on our records. Can you manage this afternoon?
M: I’m afraid not. I can manage tomorrow.
W: I’m afraid Mr. Milton is not on duty tomorrow. He’ll be here the day after tomorrow. That’s Thursday, March 27th.
M: Fine.
W: Will 5:20 be all right?
M: Well, yes. But what time is the clinic closed?
W: We start from 9:00 a.m. and close at 7:00 p.m. on weekdays. We don’t work at the weekend.
M: I’d prefer a later time so that I can come along after work.
W: Then what about 6:15?
M: Well, that’s fine.