The Guidance office WILL be open but WILL NOT do any course changes or modifications to your schedule. So, the earliest possible date to switch out/drop a course will be sometime during the first week of school where you can catch all the updates via the morning announcements.
Ack, I need to switch out of Law! I find it scary that on my first day of school my entire schedule could be switched around quite a bit. *sigh*
That being said, I'm going to go to Guidance on registration day and try and switch anyway. Yeah. I know. I'm desperate.