text: Sarah: Hi! 
  Sarah: SORRY, I totally forgot to tell you that I'm going to Rome for a conference this Friday and I can't meet you...
  Paul: Oh, I was just about to text you and ask you when we could meet...
  Paul: well.. what about Thursday after work?
  Sarah: It's doable but I'd have to check my workload
  Sarah: Sometimes it gets crazy on Thursdays and I don't get off until 6-7 pm...
  Paul: OK, when will you be able to tell for sure?
  Sarah: Tuesday at the latest
  Sarah: Sorry again for the inconvenience.
  Paul: Don't worry about it.
  Paul: I've cancelled our lessons last minute more than once... ;)
  Sarah: Thanks
  Sarah: I'll try to make it work and will get back to you tomorrow.
  Paul: OK, take care, Sarah :)
  Sarah: Byee :)
target: Sarah won't be able to come to her lesson with Paul this Friday. She's going to Rome for a conference. She'll let him know when they can meet instead until Tuesday. It's not the first time their lesson has been cancelled at the last minute.