Sales Ledger processing - print invoice - invoice date

At the moment when creating an invoice the date of the invoice defaults to the current day. This can cause issues if invoices are being created in a different period to the one they are to be posted in, if you do not remember to change the date manually. I wonder if it would be possible to have the system norm be a blank date which you have to select rather than a default current day date which has to be changed.