When is the date of the conference?

M1: The date of the computer conference has been set for next Tuesday.(44)Could you do me a favor and call the hotel we deal with to make reservations for two rooms?
M2: Sure, Paul, I will take care of it right away. But what are you going to do about the meeting you had scheduled with Mr. Nolan? Do you want me to call him and cancel?(45)
M1: Oh, I completely forgot all about him. You know, I can’t miss this meeting with him. It’s too important. On second thought, I think I’d better send Sally to New York to attend the conference with you. She has been working on the presentation, and she should be able to make the presentation in my place.(46)
M2: You’re right, but Sally might not be too happy to hear about this. I think she has a trip scheduled the week after with Mr. Singh.