Oracle Data Function Example - Trunc,add_months,Next_day ets

 --1. FIRST DAY OF PRESENT YAER
 select to_char(trunc(sysdate,'yyyy'),'day') from dual;

--2. Next year first day
select to_char (add_months(trunc(sysdate,'yyyy'),12),'day') from dual;

--3. next year first monday date.
select  next_day(add_months(trunc(sysdate,'yyyy'),12),'monday') from dual;

--4. FIRST DAY OF THE CURRENT WEEK (IT ALWAYS STARTS WITH SUNDAY)

 select trunc(sysdate) from dual;

--5. FIRST DAY OF THE NEXT WEEK
 select trunc(sysdate)+ 7 from dual;

--6. FIRST DAY OF THE PREVIOUS WEEK
 select trunc(sysdate - 7 ) from dual;

--7. FIRST DAY OF THE NEXT MONTH
 select to_char(add_months ( trunc(sysdate,'Mon'),1),'day') from dual;

--8. FIRST DAY OF THE PREVIOUS MONTH
 select to_char(add_months ( trunc(sysdate,'Mon'),-1),'day') from dual;

--9. LAST DAY OF THE PREVIOUS MONTH
 select  to_char(trunc(sysdate,'Mon')-1,'day') from dual;

--10. First day of the current quarter
 select  to_char(trunc(sysdate,'Q'),'day') from dual;

--11. First day of the previous quarter
 select  to_char(add_months(trunc(sysdate,'Q'),-3),'day')  from dual;

--12. First day of the Next quarter
 select  to_char(add_months(trunc(sysdate,'Q'),3),'day')  from dual;

--13. last day of the current week
  select trunc(sysdate)+7 from dual;

--14. last day of the next week

--15. last day of the previous week
  select trunc(sysdate)-1 from dual;

--16. Last day of the current Quarter
 select to_char(add_months(trunc(sysdate,'Q'),3)-1,'day') from dual;

--17. Last day of the previous quarter
 select to_char(trunc(sysdate,'Q')-1,'day') from dual;

--18. last day of the next Quarter.
 select to_char(add_months(trunc(sysdate,'Q'),6)-1,'day') from dual;

--19. NEXT YEAR'S FIRST MONDAY DATE
 select next_day(add_months(trunc(sysdate,'yyyy'),12),'monday') from dual;

--20. NEXT YEAR'S last day
 select to_char(add_months(trunc(sysdate,'yyyy'),24)-1 ,'day')from dual;

--21. HARD-CODING THE DATE
 select to_date('10-10-10','dd-mm-yy') from dual;

--22. NEXT YEAR'S 1ST JAN FALLS ON WHICH DAY?
 select to_char(add_months(trunc(sysdate,'yyyy'),1)-1,'day') from dual;

--23. THIS YEAR LAST DAY
 select to_char(add_months(trunc(sysdate,'yyyy'),12)-1,'day') from dual;


--24. NEXT YEAR 1ST DAY
 select to_char(add_months(trunc(sysdate,'yyyy'),24)-1,'day') from dual;

--25. Next year first monday

 select next_Day( add_months(trunc(sysdate,'yyyy'),12),'monday')  from dual;