Determining Leap Year in Oracle and Days in February

Recently, I was playing around with a leap year issue and the number of days in February. I would like to share the following snippets of commands to help some people save some time.

--2 ways to determine if it is a LEAP YEAR in ORACLE

SELECT 2008 , Decode( mod(2008, 4), 0, decode( mod(2008, 400), 0, 'Yes', decode( mod(2008, 100), 0, 'No', 'Yes') ), 'No' ) as LEAP_YEAR
FROM DUAL;

or

SELECT DECODE(29, (SELECT to_date('01032008', 'DDMMYYYY') - to_date('01022008', 'DDMMYYYY')FROM DUAL),'LEAPYEAR','NOTLEAPYEAR')
FROM DUAL;

--2 ways to determine the NUMBER OF DAYS IN FEBRUARY in ORACLE

SELECT (EXTRACT (DAY FROM LAST_DAY(ADD_MONTHS(TRUNC(TO_DATE('2008','YYYY'),'YYYY'),1))))
FROM DUAL;

or

SELECT to_date('01032008', 'DDMMYYYY') - to_date('01022008', 'DDMMYYYY')
FROM DUAL;



Of course the input to these queries requires the year that you are inquiring about.