{description}
{excerpt}For all trendline types except moving average, sets or returns the number of periods the regression should extrapolate backward.{excerpt}
{signature:C#}
 public double BackcastPeriods{ get; set; }
{signature}{signature:vb.net}
Public Property BackcastPeriods() As Double
{signature}
{remarks}
Setting this value will cause the trendline to start before the beginning of the data.
{remarks}