How to find next Xth of month after a date - sql

Question

I have two parameters :
a date (Ex : 22/11/2016)
a day number (Ex : 25)
I want to find the next 25th of month after 22/11/2016: 25/11/2016

Answer 1

select trunc(date '2016-11-22', 'month') + 25
from dual;
trunc(date '2016-11-22', 'month') will return the first of the month, the + 25 will then add the desired 25 days.
If the meaning of the second parameter depends on the "comparison" date you can do something like this:
select case
when extract(day from date '2016-11-22') >= 25 then
add_months(trunc(date '2016-11-22', 'month'), 1) + 25
else trunc(date '2016-11-22', 'month') + 25
end as next_date
from dual;
Of course you would replace the hardcoded values for the date and the "number" of days with variables or column values.
This example:
with sample_data (the_date, num_days) as (
select date '2016-11-22', 25 from dual union all
select date ' 2016-11-26', 22 from dual union all
select date ' 2016-11-26', 3 from dual
)
select the_date, num_days,
case
when extract(day from the_date) >= num_days then
add_months(trunc(the_date, 'month'), 1) + num_days - 1
else trunc(the_date, 'month') + num_days - 1
end as next_date
from sample_data;
will return:
THE_DATE | NUM_DAYS | NEXT_DATE
------------+----------+------------
2016-11-22 | 25 | 2016-11-25
2016-11-26 | 22 | 2016-12-22
2016-11-26 | 3 | 2016-12-03

Answer 2

it can solve your problem:
select
(
case
when trunc (:yourdate-trunc(:yourdate,'month'))+1 <:urNum then
trunc(:yourdate,'month')+:urNum-1
else
trunc(last_day(:yourdate))+:urNum
end)
from dual;

Answer 3

You can use
LAST_DAY(<<a date>>) + <<a day number>> + 1
LAST_DAY gives you the last day of give, months (e.i. November, 30th), then add 1 day to get 1st of December plus your day number.

Answer 4

You could use this
WITH tmp AS
(
SELECT TO_DATE('22/11/2016', 'DD/MM/YYYY') date_col FROM DUAL
)
SELECT
CASE WHEN TO_CHAR(date_col,'DD') > '25'
THEN TO_DATE('25' || TO_CHAR(ADD_MONTHS(date_col, 1), '/MM/yyyy'), 'DD/MM/YYYY')
ELSE TO_DATE('25' || TO_CHAR(date_col, '/MM/yyyy'), 'DD/MM/YYYY') END date_col_new
FROM tmp;
If your input (25) is number, you could use TO_CHAR(your_input) instead of '25'

Answer 5

Here's one way:
WITH dates AS (SELECT to_date('30/11/2015', 'dd/mm/yyyy') dt FROM dual UNION ALL
SELECT to_date('03/11/2015', 'dd/mm/yyyy') dt FROM dual UNION ALL
SELECT to_date('31/10/2015', 'dd/mm/yyyy') dt FROM dual UNION ALL
SELECT to_date('29/11/2015', 'dd/mm/yyyy') dt FROM dual UNION ALL
SELECT to_date('31/01/2016', 'dd/mm/yyyy') dt FROM dual),
dom AS (SELECT 25 day_of_month FROM dual UNION ALL
SELECT 31 day_of_month FROM dual UNION ALL
SELECT 30 day_of_month FROM dual UNION ALL
SELECT 03 day_of_month FROM dual UNION ALL
SELECT 01 day_of_month FROM dual),
res AS (SELECT dates.dt starting_dt,
dom.day_of_month,
add_months(TRUNC(dates.dt, 'mm'),
CASE WHEN to_char(dates.dt, 'dd') >= dom.day_of_month
THEN 1
ELSE 0
END) month_of_end_dt
FROM dates
CROSS JOIN dom)
SELECT starting_dt,
day_of_month,
month_of_end_dt + least(day_of_month, to_number(to_char(last_day(month_of_end_dt), 'dd'))) - 1 next_date
FROM res
ORDER BY starting_dt, day_of_month;
STARTING_DATE DAY_OF_MONTH NEXT_DATE
------------- ------------ ----------
31/10/2015 1 01/11/2015
31/10/2015 3 03/11/2015
31/10/2015 25 25/11/2015
31/10/2015 30 30/11/2015
31/10/2015 31 30/11/2015
03/11/2015 1 01/12/2015
03/11/2015 3 03/12/2015
03/11/2015 25 25/11/2015
03/11/2015 30 30/11/2015
03/11/2015 31 30/11/2015
29/11/2015 1 01/12/2015
29/11/2015 3 03/12/2015
29/11/2015 25 25/12/2015
29/11/2015 30 30/11/2015
29/11/2015 31 30/11/2015
30/11/2015 1 01/12/2015
30/11/2015 3 03/12/2015
30/11/2015 25 25/12/2015
30/11/2015 30 30/12/2015
30/11/2015 31 30/11/2015
31/01/2016 1 01/02/2016
31/01/2016 3 03/02/2016
31/01/2016 25 25/02/2016
31/01/2016 30 29/02/2016
31/01/2016 31 29/02/2016
What this does is it first finds out the month that the new date is going to be in by comparing the day you're after with the date being compared with. (ie. if the day of the date you want to get to is already past the day of the starting date, add one to the month, otherwise add nothing).
Once you have that, it's a simple matter of adding the number of days you're trying to get to.
I have assumed that if the month doesn't have the full number of days (eg. February, April, June, September, November) then you'll want whatever the last day of that month is instead.
Therefore, we'll pick whichever is lower - the last day of the month or the day you want to get to. We have to subtract one from that result since we want to include the first of the month in the count.