Specifies the time span used to search for appointments by Navigation Buttons.
A TimeSpan value, reprsenting the searched time interval.
When a Navigation button determines its state and visibility, it searches for appointments beyond the visible interval. If the calculation algorithm encounters recurring appointments in the filtered appointment subset, it searches for the end of the recurrence chain. If the appointment doesn't specify a recurrence end date, the search operation results in an endless loop which hangs the application.
To prevent this undesired behavior, use the NavigationButtonAppointmentSearchInterval property to specify a reasonable search interval.