The Administration > District Resources > District Configuration setting for "Show Which Schedules" can be set to "All" to show future Teacher/Student Schedules to ALL TEACHERS.
The iParent and iStudent Configuration setting of Show Schedule Information set to "Current & Prior" will HIDE future schedules from the students and parents. This setting "trumps" the District Configuration setting. Click here for more information.
You use District Configuration Setting "Show Which Schedules" set to "Current and Prior" to HIDE Future Teacher/Student Schedules from teachers. If you want to do this, then you would need to use Assign Teacher Access to give Administrators/Counselors/Teachers access to see Future Teacher/Student Schedules.
