So, I had a look at the SQL tables and see that the PDF invoice entries are stored in the “postmeta” table, as “_bewpi_invoice_number”, “_bewpi_invoice_year” and “_bewpi_invoice_date”.
If I change “_bewpi_invoice_date” from “June 9, 2016” to “June 29, 2015”, it still displays “June 9, 2016” on the PDF invoice, and in the Order in Woocommerce. So then I change “_bewpi_invoice_year” to “2015” and the PDF invoice completely disappear from Woocommerce.
Please help, as I need to capture historical invoices from Prestashop to Woocommerce and need to keep the dates the same, to be VAT complaint.