Classes belong to a year, a subject and one or more grade levels. Cohorts (Teaching → Cohorts) group students for the day. The timetable places classes into your operating days and periods — set them under Settings → School day, which has tabs for Operating days, Periods, Rotation (A/B or Day 1–6 schedules), Cohorts and Chapel.
Teachers see their own week under Schedule; admins see the whole school and change it with Edit schedule (Done editing when you're finished). Split-grade classes and chapel blocks are supported out of the box.
The class page
Open any class for its tabs: Stream, Plan, Students, Gradebook, Mastery, Memory work and Resources. The class's ⋯ menu holds Edit class, Message families, Take attendance, Grading settings, Lesson templates, Emergency sub plan, Sign-up sheets and Print roster.
Importing a whole timetable? Classes → ⋯ → Import classes takes a CSV.