-- =============================================
-- Description:	The invoice date ("Rechnungsdatum", ADR 0032) as a German calendar day:
--				DateFinalized (the finalisation - or, when backdated, the backdated - moment),
--				falling back to DateCreated for drafts. Both columns are stored in UTC.
--				SQL twin of Fuchs/code/InvoiceDates.IssueDate. Every list, report, export and
--				reminder that shows or groups by an invoice date uses this function (ADR 0035).
--				Also used for reminders (fds__reminder has the same DateFinalized/DateCreated pair).
-- =============================================
CREATE FUNCTION [dbo].[fds__fn_invoiceDate]
(
	@DateFinalized datetime,
	@DateCreated datetime
)
RETURNS date
AS
BEGIN
	RETURN CAST(ISNULL(@DateFinalized, @DateCreated) AT TIME ZONE 'UTC' AT TIME ZONE 'W. Europe Standard Time' AS date);
END