Query to get Next Month First Day for a given Date in Oracle

SELECT TRUNC (ADD_MONTHS (SYSDATE, 1), 'MON'), TO_CHAR (TRUNC (ADD_MONTHS (SYSDATE, 1), 'MON'), 'DD-MON-RRRR')  FROM DUAL

Script to Find All Sundays Date for a given Date Within that Year

DECLARE

   l_date       DATE := '&P_ENTER_ANY_DATE';

   l_first_sunday   DATE;

   l_last_sunday    DATE;

BEGIN

   --Find 1st Sunday

   l_first_sunday := NEXT_DAY (TRUNC (l_date, 'YYYY') - 1, 'SUN');

   --Find last Sunday

   l_last_sunday := NEXT_DAY (ADD_MONTHS (TRUNC (l_date, 'YYYY') - 1, 12), 'SUN') - 7;

   WHILE l_first_sunday <= l_last_sunday

   LOOP

      DBMS_OUTPUT.PUT_LINE ( l_first_sunday);

      l_first_sunday := l_first_sunday + 7;

   END LOOP;

END;