firstdaythismonth, lastdaythismonth, firstdayprevmonth, lastdayprevmonth,days_of_prevmonth

FIRSTDAYTHISMONTH

LASTDAYTHISMONTH

FIRSTDAYPREVMONTH

LASTDAYPREVMONTH

DAYS_OF_PREVMONTH

SELECT Trunc(SYSDATE, 'MM')                            firstdaythismonth,
       Last_day(Trunc(SYSDATE))                        lastdaythismonth,
       Trunc(Trunc(SYSDATE, 'MM') - 1, 'MM')           firstdayprevmonth,
       Last_day(Trunc(Trunc(SYSDATE, 'MM') - 1, 'MM')) lastdayprevmonth,
       Extract(DAY FROM Last_day(Trunc(Trunc(SYSDATE, 'MM') - 1, 'MM')))
                                                       days_of_prevmonth
FROM   dual; 

LeapYear SQL

SELECT CASE
         WHEN (SELECT Extract(DAY FROM Last_day(To_date('0201'
                                                        ||Extract(YEAR FROM
                                                                  SYSDATE),
                                                       'mmddyyyy')))
               FROM   dual) = '29' THEN 'LeapYear'
         ELSE 'Not A Leap Year'
       END
FROM   dual 

PeopleSoft Help: Function IsLeapYearFunction IsLeapYear(&iYear As ...

PeopleSoft Help: Function IsLeapYear
Function IsLeapYear(&iYear As ...: Function IsLeapYear Function IsLeapYear(&iYear As number) If (&iYear Mod 4 = 0) And ((&iYear Mod 100 <> 0) Or (&iYear Mod 400 = 0)) Then ...