If omitted, only the best model is retained. Applies to an existing project which already contains a forecasting model for a given series. Reevaluate specifies that previous parameter estimates will be used but that fit statistics and forecasts will be recomputed from current data and the forecasting horizon will be adjusted if the data range has changed. Refit is similar except that the model parameters are also reestimated from current data. Be sure to check either Reevaluate or Refit if you want to update previous forecasts using revised data.
All options have defaults and can be omitted.
Periods to forecast Specifies the forecasting horizon, or number of periods to forecast. The default is 12. Confidence limits Specifies the width of the confidence limits computed for the forecast. Select a value from the popup menu, or type in a value without a decimal point. The default is 95.