The seasons have fixed date ranges, so it is set manually when creating the season under “Replenishment Seasonality”.  So no auto update of them.

The seasons for one seasonality should not intersect. When you select the start and end dates for each period, these dates should belong to one year.

The system uses seasonality settings for forecasting as follows:

1. Normalizes the historical data available for the specified seasons. The sales volumes for each day of a season are divided by the appropriate seasonality factor to calculate the sales quantities as though it were a normal season.
2. Calculates the average daily sales quantity based on the historical data of the specified number of periods. For seasons within the specified periods, the system uses the normalized data.

Thank you.  To confirm I understand:  For an item that has seasonality set, when I am Preparing Replenishment, will the system automatically change the Quantity to Process based on the factor assigned to the date I am in?

As it is calculating the average daily sales value using the factor, it thus will work out how much you need to cover the average daily sales for the lead time days of the stock item.  It also adds if it needs to get stock back up to max / fulfill demand at the time.  So it will change your quantity required calculation as the factor is applied yes.  Its like saying look at the last 3 months sales to get my daily sales, but then apply a factor to it for the next 3 months season as it is a seasonal product.

Thanks very much.