A Major Event Day is defined, as per IEEE standard 1366-2003, as any day whose SAIDI figure (for the day) exceeds a certain threshold value Tmed, which is derived from the previous 5 years' worth of historical outage data (the exact procedure for that derivation is documented in IEEE standard 1366-2003). A Major Event Day is defined, as per IEEE standard 1366-2003, as any day whose SAIDI figure (for the day) exceeds a certain threshold value Tmed, which is derived from the previous 5 years' worth of historical outage data (the exact procedure for that derivation is documented in IEEE standard 1366-2003).

'Declaration
 
Public Function IsMajorEventDay( _
   ByVal outageTime As Date _
) As Boolean

'Usage
 
Dim instance As MajorEventDayManager
Dim outageTime As Date
Dim value As Boolean
 
value = instance.IsMajorEventDay(outageTime)

public bool IsMajorEventDay( 
   DateTime outageTime
)