Defines a [Date](http://schema.org/Date) or [DateTime](http://schema.org/DateTime) during which a scheduled [Event](http://schema.org/Event) will not take place. The property allows exceptions to a [Schedule](http://schema.org/Schedule) to be specified. If an exception is specified as a [DateTime](http://schema.org/DateTime) then only the event that would have started at that specific date and time should be excluded from the schedule. If an exception is specified as a [Date](http://schema.org/Date) then any event that is scheduled for that 24 hour period should be excluded from the schedule. This allows a whole day to be excluded from the schedule without having to itemise every scheduled event.