--- In firebird-support@yahoogroups.com, "Ivan Prenosil"
<Ivan.Prenosil@...> wrote:

>
> > do you now a udf function i can declare in firebird 1.5 ?
> >
> > i would like to find some data by searching on a date field format.
> >
> > i would like to extract all data for a periode,
> > for example a periode from 12 july to 24 september.
> > of course i want the query to return data for all years.
> >
> > i can do it by shaking month + day function,
> > but it would be more difficult to do.
>
> Look at builtin function
> EXTRACT(YEARDAY FROM yourfield)
>
> Do you require the select to use index ?

YEARDAY for a specific date will be different during leap years from
March onwards.

Adam