This schedule basically shows you the classes each house can take and you can customize your own schedule. You can have your character have some extra classes, more than four periods. I have a list below the schedule that shows you all of the extra classes you can take and extra activities.
Here are the electives, these electives become accessible to every student upon their third year at Hogwarts. You can only pick 3 classes out of these.
*Study of Ancient Runes
*Arithmancy
*Muggle Studies
*Care of Magical Creatures
*Divination
*Apparition (Sixth Years only)
*Alchemy( Sixth Years and up only)
Extracurricular
These classes are held after their immediate classes basically like an after school program type thing. You can pick as many as these classes as your character can handle but just to make sure, some classes do start at the same time so keep that in mind.
*Ancient Studies
*Art
*Earth Magic
*Muggle Art
*Music
*Muggle Music
*Ghoul Studies
*Magical Theory
*Xylomancy
*Frog Choir
*Hogwarts orchestra