Here you enter the invoice date that appears on the invoice. The field shows today's date by default. The Invoice date and Payment terms are the basis that is used to calculate the invoice's due date.
It is possible to determine that the invoice date should automatically be used both as preliminary coding date and as voucher date. If the invoice date would be changed afterwards, both the other dates would also be altered. This is determined by the setting Suggest same voucher date as invoice date, under the section Accounts Payable under the Purchase tab in the Settings procedure.
You can change the invoice date on an already registered invoice even if it is final coded. This applies as long as neither of the ledgers has been reset. If a ledger has been reset the field becomes grey (inactive) and cannot be modified.