Exempt Employees Working 180 Days

Coriolanus

Our educational organization has many employees who work a 180-day work year, and their salaries are based on this shortened work year. Most of them are exempt. Sometimes they are required to work extra days or parts of days. Can we expect them to do so without extra pay? Do we jeopardize their exempt status if we do pay them extra? Do they have a "right" to expect a day off if they work on non-scheduled days? We have no written policy and are planning to prepare one. I'd appreciate any help I can get on the issues to be considered.