How to set the maximum number of periods per session for a subject?

[danghoan]

For example: I have Physics as 2 periods a week for each class. But in one session, I want to only study 1 lesson (Not allowed to have 2 classes in the same session).
I don't know where to set it up in the software. Can you guide me? (If possible, can you show me an illustration when selecting that condition) Thank you very much!

[Liviu Lalescu]

Session = day? Then, constraint min 1 days between activities.

[danghoan]

Thank you very much