if you want them to come, then they can come. but if you make enough decisions before the day, and have them on the end of your phone line, then you should be ok without them.
before the day you have to have your timetable worked out, so that will be done.
also in the book it is only giving 1/2 hour slots for each subject... huh? i don't understand that part, i am sure it ewill tak elonger than that