I don't get this, scheduling classes in HS. Maybe things have changed, I will find out next year. But when I was in HS, you didn't schedule yourself, it was scheduled for you and everyone, and I mean everyone took a lunch, in fact it wa right in the middle of my language arts class. This class was extra long to accommodate lunch period.
My dd just had to choose her classes for next year(11th grade) She doesn't get to pick the periods that she will have the classes but she does get to choose which classes she will take. I went to high school 100 years ago(Catholic school) and I remember being able to choose some of my classes.