Querying date interval

Hi,

Is there any SQL workaround to get the right results from the select
statement bellow? Or am I doing something wrong??

create table testdate (field1 date);
insert into testdate values ('2000-09-30');
insert into testdate values ('2000-10-20');
insert into testdate values ('2000-11-25');

select * from testdate where field1 between '2000-10-01' and
'2000-11-30' ;
  field1
------------2000-09-30   <---- why is it here??2000-10-202000-11-25
(3 rows)

Thanks in advance!
--
Renato
Sao Paulo - SP - Brasil
rdg@viafractal.com.br