Get Last date of month SQL - sql

Question

I need to find the last day of a month in the american (mm-dd-yyyy) format for a column which has yymm(nvarchar format).
example:- for 1601---> 01-31-2016
Thank you for help!

Answer 1

Using convert to get the date of the 1st of the month, then dateadd to get the next month, and one more dateadd to get one day before:
DECLARE #D char(4) = '1601'
SELECT DATEADD(DAY, -1, DATEADD(MONTH, 1, CONVERT(date, #D + '01', 12)))
Result:
2016-01-31

Answer 2

With a string of 1601, we just need to append a 01 because the century will be assumed. This new string of 160101 can be converted into a date.
Example
select convert(varchar(10),dateadd(day,-1,dateadd(month,1,YourCol+'01')),101)
From YourTable
Returns
01/31/2016

Answer 3

Since you said year 20XX...
declare #oddDate nvarchar(4) = '1601'
select
DATEADD(d, -1, DATEADD(m, DATEDIFF(m, 0, '20' + cast(YY as varchar(2)) + cast(MM as varchar(2)) + '01') + 1, 0)) as LastDayof20Year
,'20' + cast(YY as varchar(2)) + cast(MM as varchar(2)) + '01' as MadeUpDate
from
(select
left(#oddDate,2) as YY
,right(#oddDate,2) as MM) x
Or simply...
select
DATEADD(d, -1, DATEADD(m, DATEDIFF(m, 0, '20' + cast(left(#oddDate,2) as varchar(2)) + cast(right(#oddDate,2) as varchar(2)) + '01') + 1, 0)) as LastDayof20Year

Answer 4

Something like the following should do the trick...
IF OBJECT_ID('tempdb..#TestData', 'U') IS NOT NULL
DROP TABLE #TestData;
CREATE TABLE #TestData (
CharDate CHAR(4) NOT NULL
);
INSERT #TestData (CharDate) VALUES
('9801'), ('9902'), ('0012'), ('0202'), ('1005'), ('1503');
--============================================================
SELECT
FormattedEOM = CONVERT(CHAR(10), em.EndOfMonth, 101)
FROM
#TestData td
CROSS APPLY ( VALUES (CASE WHEN CAST(LEFT(td.CharDate, 2) AS INT) > 30 THEN '19' ELSE '20' END) ) c (Century)
CROSS APPLY ( VALUES (DATEFROMPARTS(CONCAT(c.Century, LEFT(td.CharDate, 2)), RIGHT(td.CharDate, 2), 1)) ) fm (FirstOfMonth)
CROSS APPLY ( VALUES (EOMONTH(fm.FirstOfMonth)) ) em (EndOfMonth);
HTH,
Jason
Edit: The following should work with 2008....
SELECT
FormattedEOM = CONVERT(CHAR(10), em.EndOfMonth, 101)
FROM
#TestData td
CROSS APPLY ( VALUES (CASE WHEN CAST(LEFT(td.CharDate, 2) AS INT) > 30 THEN '19' ELSE '20' END) ) c (Century)
CROSS APPLY ( VALUES (CAST(c.Century + td.CharDate + '01' AS DATE)) ) fm (FirstOfMonth)
CROSS APPLY ( VALUES (DATEADD(mm, 1, fm.FirstOfMonth)) ) nm (NextMonth)
CROSS APPLY ( VALUES (DATEADD(dd, -1, nm.NextMonth)) ) em (EndOfMonth);