Currently the API only contains the document date (invoiceDate, orderDate, etc). The Posting Date is not exposed via the API and on record creation it is set to the current date.

This makes the API unusable for creating records as the Posting Date determines the dates for the corresponding G/L entries and VAT entries. Especially the latter is painful as (in NL) we are required by law to use the document date as the date for VAT entries.

Please either set the Posting Date to the same value as the document date (on creation and updates) or, probably more flexible, expose the Posting Date as a seperate property.