I am applying in neuro as well as to several prelim/TY programs. I got an interview invite at a TY program. Ideally, it would be great to try a coordinate the interview date with any interviews I get for neuro programs or other prelim programs in the same city. How long is it acceptable/smart/polite to wait to sign up for an interview date for the purpose of attempting to coordinate interview dates? Also, once you select an interview date, how flexible are programs about changing the date if you then get another interview in the same city and you want to coordinate? I don't want to risk pissing off the program or losing my interview date, but saving hundreds of dollars on flights is a big win...