What is the purpose of exception scheduling in BAS?

• A. It permanently changes the main schedule.
• B. It disables all schedules.
• C. Exceptions allow overrides for holidays or events without altering the main schedule.
• D. It duplicates the main schedule.

Answer: (C)

Exception scheduling in a BAS is an overlay mechanism that lets you adjust the normal operation for specific dates or events. The main schedule stays intact, and an exception modifies behavior only during the defined holiday or event window. For example, you can set the HVAC to a reduced cooling setpoint and energy-saving mode on a holiday, without changing the regular weekday schedule. When the exception period ends, the system automatically reverts to the main schedule. This approach keeps the baseline plan clean and auditable while giving flexibility for one-off conditions. It prevents permanent edits to the main schedule, avoids turning off or disabling all schedules, and isn’t simply duplicating the entire schedule—it's applying a temporary override that can be scheduled or triggered by a calendar event. Understanding this helps in planning energy use and occupant comfort around known variations, like company holidays, special events, or occupancy changes, without complicating the standard operation.