This property works with the DiscardTimeUnit property and indicates a time interval in which Historic data is stored on a database table, until it is discarded. Default value of this property is 1 (one time unit indicated by the DiscardTimeUnit property). If this property is set to a value less than the value of the BackupDiscardInterval property, Elipse Water automatically sets the value of the BackupDiscardInterval property as double the value of this property.