That's basically how it is -- every class is only one semester. It can vary -- basically 3 of the 4 classes are the same every day and the other 1 works on an A/B schedule for a few elective type classes and phys ed.. The scheduling system makes it EXTREMELY difficult to work in any arts/music/foreign language classes and that's becoming a major issue in our high school. It has almost gotten to the point where choir, band, and orchestra have to be after-school activities or they overlap with another class and the student is forced to skip lunch to be able to participate in those groups. It is literally impossible to be in choir and take a foreign language in one semester -- they're only offered during mod 3....period. We hired a new superintendent last year who is very pro arts and she is trying to make changes but it's going to take some time. I could go on and on about block scheduling but I won't.
Anyway, it's pretty much standard that you have the same classes every day for half the year and then in switch to all new classes for the second semester. So you only have Humanities, Math, etc. for half the year. That's why it's so difficult to miss more than a day or two of school because everything is so condensed. And since the AP tests are given about a month before school is over, those classes are even MORE intense as they have less time to cover all of the material and still have time for reviews and practice.