Can you confirm if the action date will be the made up date for the accounts and the annual return. Also what form types will contain data in this field?
Yes, the action date for the accounts and annual returns is the made up date.
The documentation is in the process of being reviewed and we plan to publish which form types have the action_date field.
Was the API documentation ever updated / published with the "action_date" parameter? I've tried searching the filingHistory resources and can't seem to find any reference to it so any insight into which form types return this parameter and also it's official description would be greatly appreciated.