SAP IQ translator's pushdown of DATEADD function is wrong.
The function DATEADD has following signature in SAP IQ:
DATEADD ( date-part, numeric-expression, date-expression )
the date-part is of type Date Part, see (1).
Teiid is currently pushing DATEADD function with date-part argument as string, which causes an error. It should be Date Part identifier, e.g. instead of 'DAY', it should be DAY.