Hi jeroenbackx,
I can help you out with your question.
It sounds like a Recurring Event is what you are asking for, unless you are asking to hide some of the recurrences.
You can setup an Event(Class) and a recurrence with the Start and End Date and then choose the recurrence period for weekly. This way if the classes runs on a Thursday it will only show in your calendar every Thursday during that period.
We do have an option in the settings called “Recurring event instances” but then it does not hide in the month view.
If you would like to selective hide recurrences in the month view the only option will be to do some customization to the coding.
Does that help? Let me know if I was off on what you are trying to do and I can provide some more information.
Thanks