On 18 Nov 2008, at 07:26, skoczian wrote:

> The following is taken straight from the Firebird Book, Supplement 2,
> Appendix I Function Summary, p. 249:
>
> SQL> SELECT DATEADD(WEEK, 1, DATE 'YESTERDAY') FROM RDB$DATABASE;;
>
> Result (in ISQL, Firebird 2.1, Windows XP):
>
> DATEADD
> ===========
> Statement failed, SQLCODE = -833
> expression evaluation not supported
>
> DAY, MONTH, YEAR work as expected. And in the notes for the DATEADD
> function WEEK is missing. So I'm not quite sure if it really should
> work.

Don't think it does. We have

DATEADD(DAY, %2*7, CAST(%3 AS TIMESTAMP))

in our code for FB 2.1.

HTH
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