Can be found out by using below method :

select TRUNC(sysdate+1, 'Q'),TRUNC(ADD_MONTHS(sysdate, +3), 'Q')-1 from dual

for statement : select TRUNC(sysdate+1, 'Q'),TRUNC(ADD_MONTHS(sysdate, +3), 'Q')-1 from dual

TRUNC(sysdate+1, 'Q') -- 1st date of quarter (+1 is not required, it will return the wrong first date of quarter if the date becomes last day of a given quarter. So, the statement should be like below :

select TRUNC(sysdate, 'Q'),TRUNC(ADD_MONTHS(sysdate, +3), 'Q')-1 from dual

Tanmoy,
That was exactly what I was looking, concise and precise code

Regards
John

this is how do I calculate end of quarter ignoring days off:

with

calendar1 as
(select * from
(select to_date('29.03.2012','DD.MM.YYYY') as arcdate, 0 as dayoff from dual union all
select to_date('30.03.2012','DD.MM.YYYY') as arcdate, 0 as dayoff from dual union all
select to_date('31.03.2012','DD.MM.YYYY') as arcdate, 1 as dayoff from dual)
where dayoff = 0),

end1 as
(select TRUNC(ADD_MONTHS(to_date('25.03.2012','DD.MM.YYYY'), +1), 'Q')-1 as end_of_quarter from dual)

select max(calendar1.arcdate) as end_of_quarter
from calendar1, end1
where calendar1.arcdate <= end1.end_of_quarter


I need to create list of end_of_quarter for period "between sysdate MINUS two years and sysdate PLUS two years". Please note, dayoff is not only Saturday and Sunday, but it's also state holiday, etc. In real life table calendar1 is updated by central bank.

Could you please suggest me some decision?

here is decision for ignoring dayoff (table calendar1 should be updated):


with calendar1 as (select *
from (select to_date('29.03.2012','DD.MM.YYYY') as arcdate, 0 as dayoff from dual union all
select to_date('30.03.2012','DD.MM.YYYY') as arcdate, 0 as dayoff from dual union all
select to_date('31.03.2012','DD.MM.YYYY') as arcdate, 1 as dayoff from dual)
where dayoff = 0),
end1 as (select TRUNC(ADD_MONTHS(sysdate, (level - 8)*3), 'Q') start_of_quarter,
ADD_MONTHS(TRUNC(ADD_MONTHS(sysdate, (level - 8)*3), 'Q'), +3)-1 as end_of_quarter
from dual
connect by level <= 16)
select e1.start_of_quarter, nvl(max(c1.arcdate), e1.end_of_quarter) as actual_end_of_quarter
from calendar1 c1,
end1 e1
where c1.arcdate(+) between e1.start_of_quarter
and e1.end_of_quarter
group by e1.start_of_quarter, e1.end_of_quarter

SELECT TO_CHAR(TRUNC(SYSDATE,'q')-1,'yyyy')||'-Q'||TO_CHAR(TRUNC(SYSDATE,'q')-1,'Q') AS LAST_QUARTER, TO_CHAR(TRUNC(SYSDATE,'mm'),'MON-yyyy')
CURRENT_MONTH from dual;

variable v_year    number

variable v_quarter number

exec :v_year     :=2017

exec :v_quarter:=4

select :v_year    as year,
       :v_quarter as quarter,
       to_date(:v_year||to_char(-2+3*:v_quarter,'fm00'),'yyyymm')        as quarter_start,
       last_day(to_date(:v_year||to_char(3*:v_quarter,'fm00')||'01 23:59:59','yyyymmdd hh24:mi:ss')) as quarter_end
from dual a;


YEAR|QUARTER|QUARTER_START      |QUARTER_END        
2017|      4|2017-10-01 00:00:00|2017-12-31 23:59:59

This calculates for current year based on Tom's code

select level as quarter,
add_months( TRUNC(CURRENT_DATE, 'YYYY'), (level -1) *3 ) "First Day Of Quarter",
last_day(add_months( TRUNC(CURRENT_DATE, 'YYYY'), (level -1) *3 +2 ) ) "Last Day of Quarter"
from dual connect by level <= 4;