answer: Tim Green calls #Person2# twice to change the wake-up call from 5:30 to 6:30 am.
documents: #Person1#: What can I do for you, sir?
  #Person2#: I am Tim Green in Room 1021 and I want a wake-up call at five thirty AM tomorrow.
  #Person1#: Yes, I see. five thirty AM Mr. Green, Room 1021.
  #Person2#: I want to change my wake-up time.
  #Person1#: Ok, could you tell me your room number and your name?
  #Person2#: Tim, in Room 1021.
  #Person1#: And when would you want us call you this time?
  #Person2#: At six thirty AM tomorrow.
  #Person1#: Ok, six thirty AM. We will call you exactly on that time.