In Switzerland, each university has its own right when to start it’s semester. Thus, the academic calendar changes from one organisation to another. Some public universities start in the middle of September, while others start from the first dates of the month.
Huge variety can be seen among private universities as well. Traditionally, start time in September is shared among many, but some private entities have the end of September or even first dates of October as a start date.
That’s why exams week also differs from one case to another. Students need to keep that in mind, when one is planning winter/summer break ahead.