You can change your rotation - I did. I just returned from 3/12 - 3/19/05 7-day western and changed from PLA to APL in Rockin D Bar where you sign up for Palos.
If you charge your tips to your room, the name on your tickets will be wrong since you changed rotation but just scratch it out and put your servers name and it works out. Just be sure to give it to the correct server.