Should commercial invoice and packing list show the same issuance date?

Exporters create packing list and commercial invoice on the same day for a regular international trade transaction.

But in some occasions one of the documents may need to be created earlier than the other.

For example, certified invoices or legalized invoices may have to be created earlier than the packing list, as certification and legalization process takes quite a long time.

Especially if the selected payment method is letter of credit, exporters frequently ask a common question in regards to the dates of the packing lists and commercial invoices.

Should commercial invoice and packing list show the same issuance date under letter of credit rules?