answer: Uncle Smith invites Cathy to his birthday party. Cathy will be busy on Saturday so they agree on Sunday.
documents: #Person1#: Good morning, Uncle Smith.
  #Person2#: Good morning, Cathy.
  #Person1#: I want to have a dinner party to celebrate my birthday. Would you come?
  #Person2#: I'd love to, Cathy. What time?
  #Person1#: Next weekend, on Saturday.
  #Person2#: Saturday do you say?
  #Person1#: If that's all right with you.
  #Person2#: I'm afraid I'm busy then. I've already had plans.
  #Person1#: What about Sunday?
  #Person2#: I'm sure it will be all fight.
  #Person1#: Good, you'd better around 6:30 or 7:00, we'll heve time to chat a while.