Field help (SHIDATSDH) 

The shipment date is the date used to determine the date of the good issue. 
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.