> I would like ask if there is any way in Firebird extract week number
> from
> date (so number between 1 and 52(53?)) ?
> Syntax like
> extract(week from d)

No, but you can use simple stored procedure
http://www.volny.cz/iprenosil/interbase/ip_ib_code_timestamp.htm#_code3_weekofyear

Ivan