This is the stock actual posting date: it is used as posting date in the stock journal.
If the delivery comes from an order, the shipment date is initialized according to the value of parameter INISHIDAT - Shipment date initialization (chapter VEN, group SSD). It can be:
A delivery note cannot be validated with a shipment date greater than the current date.
In the case of an order delivery, if this date is changed, a message is displayed, proposing a new price list search when the user parameter SDHRECPRI - Order delivery price search (chapter VEN, SSD group) is set to 'Yes'. When it is set to ‘No’, the price of the order is kept.