create table financialyear
(fiscal_year integer not null primary key,
start_date date not null,
check ((extract(year from start_date)=fiscal_year-1)
and (extract (month from start_date)=10)
and (extract(day from start_date)=1),
end_date date not null,
constraint valid_end_date
check ((extract (year from end_date)=fiscal_year)
and (extract (month from end_date)=9)
and (extract (day from end_date)=30)))
