Check if a given year is a leap year in PL/SQL

isLeapYear(year):
begin
   if year is divisible by 4 and not divisible by 100, then
      it is leap year
   else if the number is divisible by 400, then
      it is leap year
   else
      it is not leap year
end

DECLARE
   year NUMBER := 2012;
BEGIN
   IF MOD(year, 4)=0
      AND
      MOD(year, 100)!=0
      OR
      MOD(year, 400)=0 THEN
      dbms_output.Put_line(year || ' is leap year ');
   ELSE
      dbms_output.Put_line(year || ' is not leap year.');
   END IF;
END;

2012 is leap year