Here you can enter a general delivery date (or delivery period) for the order. The entered date will become default on the first order row.
The delivery date can also consider Transport time, that has been entered for the customer and will be deducted from the entered date. This is determined by the setting Deduct transport time from delivery period during order registration?, under the section Orders / Quotes under the Sales tab in the Settings procedure.
If you change the delivery date on an existing order, you can also replan the order with a new delivery period on each order row. A control question will therefore appear after you have changed the delivery date, where you can decide whether both the current period and the initial period shall be updated and the initial period be moved to the requested period or if only the current period is to be changed. Alternatively, you can also select not to update any of the rows.
The order header's delivery date is not printed on any documents. It is always the delivery period on the order rows that applies.