How do teachers not have two consecutive days off? Thank you!
Sorry, I cannot think of a solution.
As a workaround:
Don't use constraint teachers max days.
Add a new subject. Maybe call it "---" or "free".
If a teacher have got 2 free days, then give him 2 new activities with subject "free" but no students. These activities need highest possible duration (so the number of hours per day or the number of max allowed working hours for the teacher). Set constraint min 2 days between this activities.
Thank you very much!