My scenario is as below:
#StartDate = 13th of current month
#EndDate = 12th of next month.
I want to get all the date with the day-name for Mondays, Tuesdays, Wednesdays, Thursdays, Fridays, Saturdays and Sundays lying between the start and end date.
Try this:
declare #startDate datetime = '2016-01-13'
declare #endDate datetime = '2016-02-12'
;with dateRange as
(
select [Date] = dateadd(dd, 1, #startDate)
where dateadd(dd, 1, #startDate) < #endDate
union all
select dateadd(dd, 1, [Date])
from dateRange
where dateadd(dd, 1, [Date]) < #endDate
)
select [Date], datename(dw,[Date])
from dateRange
To count the number of each day as per your comment (this should be part of the question really), change the last part of James' answer to this:
select datename(dw,[Date]) as day_name, count([Date]) as number_days
from dateRange group by datename(dw,[Date]), datepart(DW,[Date])
order by datepart(DW,[Date]);
You can try something like this :
DECLARE #StartDate DATETIME
DECLARE #StartDateFixed DATETIME
DECLARE #EndDate DATETIME
DECLARE #NumberOfDays int
SET #StartDate = '2016/01/01'
SET #EndDate = '2016/01/02'
SET #NumberOfDays = DATEDIFF(DAY,#StartDate,#EndDate) + 1
SET #StartDateFixed = DATEADD(DD,-1,#StartDate)
SELECT WeekDay , COUNT(WeekDay)
FROM (
SELECT TOP (#NumberOfDays) WeekDay = DATENAME(DW , DATEADD(DAY,ROW_NUMBER() OVER(ORDER BY spt.name), #StartDateFixed))
FROM [master].[dbo].[spt_values] spt
) A
GROUP BY WeekDay
The output will be
WeekDay
------------------------------ -----------
Friday 1
Saturday 1
(2 row(s) affected)
In case if you need to get current and next date from date number specified such as 13 and 12
Current Month
DECLARE #cur_mont INT = (SELECT MONTH(GETDATE()))
Current Year
DECLARE #cur_year INT = (SELECT YEAR(GETDATE()))
Next Month
DECLARE #nxt_mont INT = (SELECT MONTH(DATEADD(month, 1, GETDATE())))
Next Month year (In case of December year change)
DECLARE #nxt_year INT = (SELECT YEAR(DATEADD(month, 1, GETDATE())))
Create start date
DECLARE #startDate DATETIME = (SELECT CAST(CAST(#cur_year AS varchar) + '-' + CAST(#cur_mont AS varchar) + '-' + CAST(13 AS varchar) AS DATETIME))
Create end date
DECLARE #endDate DATETIME = (SELECT CAST(CAST(#nxt_year AS varchar) + '-' + CAST(#nxt_mont AS varchar) + '-' + CAST(12 AS varchar) AS DATETIME))
Dates between start and end date
SELECT TOP (DATEDIFF(DAY, #startDate, #endDate) + 1)
DATEADD(DAY, ROW_NUMBER() OVER(ORDER BY a.object_id) - 1, #startDate) AS Date,
DATENAME(DW, DATEADD(DAY, ROW_NUMBER() OVER(ORDER BY a.object_id) - 1, #startDate)) AS Day
FROM sys.all_objects a CROSS JOIN sys.all_objects b;
DECLARE #dayStart int = 13, --The day of current month
#dayEnd int = 12, --The day of another month
#howManyMonth int = 1, --How many month to take
#dateStart date,
#dateEnd date
--Here we determine range of the dates
SELECT #dateStart = CONVERT (date,
CAST(DATEPART(Year,GETDATE()) as nvarchar(5))+ '-' +
CASE WHEN LEN(CAST(DATEPART(Month,GETDATE()) as nvarchar(5))) = 1
THEN '0'+CAST(DATEPART(Month,GETDATE()) as nvarchar(5))
ELSE CAST(DATEPART(Month,GETDATE()) as nvarchar(5)) END + '-' +
CAST (#dayStart as nvarchar(5))),
#dateEnd = CONVERT (date,
CAST(DATEPART(Year,DATEADD(Month,#howManyMonth,GETDATE())) as nvarchar(5))+ '-' +
CASE WHEN LEN(CAST(DATEPART(Month,DATEADD(Month,#howManyMonth,GETDATE())) as nvarchar(5))) = 1
THEN '0'+CAST(DATEPART(Month,DATEADD(Month,#howManyMonth,GETDATE())) as nvarchar(5))
ELSE CAST(DATEPART(Month,DATEADD(Month,#howManyMonth,GETDATE())) as nvarchar(5)) END + '-' +
CAST (#dayEnd as nvarchar(5)))
;WITH cte AS (
SELECT #dateStart as date_
UNION ALL
SELECT DATEADD(day,1,date_)
FROM cte
WHERE DATEADD(day,1,date_) <= #dateEnd
)
--Get results
SELECT DATENAME(WEEKDAY,date_) as [DayOfWeek],
COUNT(*) as [DaysCount]
FROM cte
GROUP BY DATEPART(WEEKDAY,date_),
DATENAME(WEEKDAY,date_)
ORDER BY DATEPART(WEEKDAY,date_)
OPTION (MAXRECURSION 0)
Output:
DayOfWeek DaysCount
----------- -----------
Sunday 4
Monday 4
Tuesday 4
Wednesday 5
Thursday 5
Friday 4
Saturday 4
(7 row(s) affected
I need to generate either a column in a query or a temp table (not sure which one is required)
so that I can have a list of dates that are on Saturday that fall within a given date range.
This list will be used in a join to associate records with weeks.
What are my options?
Sample Input:
From: 03/01/2013
To: 04/30/2013
Results:
Week Ending
- 03/02/2013
- 03/09/2013
- 03/16/2013
- 03/23/2013
- 03/30/2013
- 04/06/2013
- 04/13/2013
- 04/20/2013
- 04/27/2013
- 05/04/2013
Current code:
create table #TBL7(YEAR INT, WEEKNUMBER INT, STARTDATE DATETIME, ENDDATE DATETIME)
begin
declare #startdate datetime
, #enddate datetime
, #ctr int
SET #startdate = CAST(2013 AS VARCHAR)+ '/01/01'
SET #enddate = CAST(2013 AS VARCHAR) + '/12/31'
SET #ctr = 0
WHILE #enddate >= #startdate
BEGIN
SET #ctr = #ctr + 1
INSERT INTO #TBL7
values(year(#startdate), #ctr, #startdate, #startdate + 6)
SET #startdate = #startdate + 7
END
end
select * from #TBL7
First, create a calendar table. Then you have a very simple query:
select [Date]
from dbo.Calendar
where DayOfWeek = 'Saturday' and [Date] between '20130301' and '20130430'
A calendar table is almost always the best approach to working with dates because you're working with data, not code, so you can see it's correct and there's no cryptic code to maintain.
This is Oracle code. Sorry I do not know how to convert this to SQL SERVER. Should not be very hard. All you need is to use proper functions in place of to_date() and to_char(), and calc the difference between start and end date, e.g. (end_date-start_date)+1:
WITH data(r, some_date) AS
(
SELECT 1 r, to_date('03/01/2013', 'MM/DD/YYYY') some_date FROM dual
UNION ALL
SELECT r+1, to_date('03/01/2013', 'MM/DD/YYYY')+r FROM data WHERE r < 61 -- (end_date-start_date)+1
)
SELECT some_date
, To_Char(some_date, 'DY') wk_day
FROM data
WHERE To_Char(some_date, 'DY') = 'SAT'
/
SOME_DATE WK_DAY
--------------------
3/2/2013 SAT
3/9/2013 SAT
3/16/2013 SAT
3/23/2013 SAT
3/30/2013 SAT
4/6/2013 SAT
4/13/2013 SAT
4/20/2013 SAT
4/27/2013 SAT
This should work:
WITH cteWeeks (WeekEnding) As
(
-- Find the Saturday of the first week.
-- Need to allow for different DATEFIRST settings:
SELECT
CASE
WHEN DatePart(dw, DateAdd(day, ##datefirst, #StartDate)) = 7 THEN #StartDate
ELSE DateAdd(day, 7 - DatePart(dw, DateAdd(day, ##datefirst, #StartDate)), #StartDate)
END
UNION ALL
SELECT
DateAdd(day, 7, WeekEnding)
FROM
cteWeeks
WHERE
WeekEnding < #EndDate
)
SELECT
WeekEnding
FROM
cteWeeks
;
http://www.sqlfiddle.com/#!3/d41d8/12095
I would like select data between two date, without day
An input example:
start month: 9 , start year: 2011
end month: 3, end year: 2012
I think that there are two way to do this.
The first is convert start month and start year to date like 2011-09-01 and convert last date to 2012-03-31, but this requires calculation of the last day of end month. Obtained these date we can use a BEETWEN function for the WHERE clause (but, is the CONVERT function reliable?)
The second solution is to use the DATEPART function like in the following code:
I try to explain: if end year is equal to the initial year, then month must be between the start and end months; else if the final months is greater than the initial years if different from the initial and final year, I take everything in between; else if the final year, the month must be less than or equal to the final month, if the initial year, month must be greater than or equal to the final month
Can you help me do this in the best way? Is correct, the solution I adopted?
declare #IndDebitoCredito bit,#ProgTributo int,#mi as integer,#ai as integer,#mf as integer,#af as integer,#IDAnagrafica varchar(5)
select #mi = 01,#ai = 2011,#mf = 12,#af = 2011,#IDAnagrafica = 'DELEL',#IndDebitoCredito = 1
select distinct rrd.IDTributo
from TBWH_Delega d
--inner join TBWH_SezioneDelega sd on d.IDDelega = sd.IDDelega
inner join TBWH_Rigo rd on rd.IDDelega = d.IDDelega
inner join TBWH_RataRigo rrd on rrd.IDRigo = rd.IDRigo
where
(
DATEPART(MM,d.DataDelega)<=#mf and
DATEPART(MM,d.DataDelega)>=#mi and
DATEPART(YYYY,d.DataDelega)=#ai and
#af = #ai
)
OR
(
--anno finale magg. anno iniziale
#af > #ai AND
(
( -- delega nell'intervallo
DATEPART(YYYY,d.DataDelega)<#af AND
DATEPART(YYYY,d.DataDelega)>#ai
-- DATEPART(MM,d.DataDelega)>=#mi
)
OR
( -- delega limite destro
DATEPART(YYYY,d.DataDelega)=#af AND
DATEPART(MM,d.DataDelega)<=#mf
)
OR
( -- delega limite sinistro
DATEPART(YYYY,d.DataDelega)=#ai AND
DATEPART(MM,d.DataDelega)>=#mi
)
)
)
GO
Your first solution is almost there, but is more complicated than it needs to be and won't work anyway. It will miss out any rows from the last day of the end month.
You can add one month to the end month and then use BETWEEN on the first of each month. eg.
start month: 9 , start year: 2011
end month: 3, end year: 2012
BETWEEN '2011-09-01' AND '2012-04-01'
or, as JNK points out, this will be better:
DataDelega >= '2011-09-01' AND DataDelega < '2012-04-01'
You'll need to add in some logic to deal with the end month being December, but this looks like the simplest way of doing it.
You are WAY overcomplicating this. You really only need two comparisons:
Is the month and year after or equal to the initial value?
Is the month and year before or equal to the final value?
Try:
SELECT *
FROM MyTable
WHERE Datefield BETWEEN
CAST(#mi as varchar) + '/1/' + CAST(#ai as varchar)
-- first of first month
AND
DATEADD(DAY, -1, (DATEADD(Month, + 1, (CAST(#mf as varchar) + '/1/' + CAST(#af as varchar)))))
-- Last day or final month
SELECT *
FROM Table
WHERE DateField
BETWEEN CONVERT(DATE, CONVERT(CHAR(4), #ai) + RIGHT('00' + CONVERT(VARCHAR(2), #mi), 2) + '01', 112)
AND DATEADD(DD, -1, DATEADD(MM, 1, CONVERT(DATE, CONVERT(CHAR(4), #af) + RIGHT('00' + CONVERT(VARCHAR(2), #mf), 2) + '01', 112)))
Avoid using expressions on the DateField columns, as it makes query not SARGable.
I would use:
WHERE DateToCheck >= --- first day of StartMonth
DATEADD( mm, #StartMonth-1,
DATEADD( yy, #StartYear-2000, '2000-01-01')
)
AND DateToCheck < --- first day of next month (after EndMonth)
DATEADD( mm, #EndMonth,
DATEADD( yy, #EndYear-2000, '2000-01-01')
)
DECLARE #mi INT
, #ai INT
, #mf INT
, #af INT
SELECT #mi = 01
, #ai = 2011
, #mf = 12
, #af = 2011
--local variables to hold dates
DECLARE #i DATETIME
, #f DATETIME
--build strings to represent dates in YYYYMMDD format
--add a month to the #f date
SELECT #i = CONVERT(VARCHAR(4), #ai) + RIGHT('0' + CONVERT(VARCHAR(2), #mi),
2) + '01'
, #f = DATEADD(month, 1,
CONVERT(VARCHAR(4), #af) + RIGHT('0'
+ CONVERT(VARCHAR(2), #mf),
2) + '01')
--select data where date >= #i, and < #f
SELECT *
FROM MyTable
WHERE DateField >= #i
AND DateField < #f
I need to determine the number of days in a month for a given date in SQL Server.
Is there a built-in function? If not, what should I use as the user-defined function?
In SQL Server 2012 you can use EOMONTH (Transact-SQL) to get the last day of the month and then you can use DAY (Transact-SQL) to get the number of days in the month.
DECLARE #ADate DATETIME
SET #ADate = GETDATE()
SELECT DAY(EOMONTH(#ADate)) AS DaysInMonth
You can use the following with the first day of the specified month:
datediff(day, #date, dateadd(month, 1, #date))
To make it work for every date:
datediff(day, dateadd(day, 1-day(#date), #date),
dateadd(month, 1, dateadd(day, 1-day(#date), #date)))
Most elegant solution: works for any #DATE
DAY(DATEADD(DD,-1,DATEADD(MM,DATEDIFF(MM,-1,#DATE),0)))
Throw it in a function or just use it inline. This answers the original question without all the extra junk in the other answers.
examples for dates from other answers:
SELECT DAY(DATEADD(DD,-1,DATEADD(MM,DATEDIFF(MM,-1,'1/31/2009'),0))) Returns 31
SELECT DAY(DATEADD(DD,-1,DATEADD(MM,DATEDIFF(MM,-1,'2404-feb-15'),0))) Returns 29
SELECT DAY(DATEADD(DD,-1,DATEADD(MM,DATEDIFF(MM,-1,'2011-12-22'),0))) Returns 31
--Last Day of Previous Month
SELECT DATEPART(day, DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,GETDATE()),0)))
--Last Day of Current Month
SELECT DATEPART(day, DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,GETDATE())+1,0)))
--Last Day of Next Month
SELECT DATEPART(day, DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,GETDATE())+2,0)))
Personally though, I would make a UDF for it if there is not a built in function...
I would suggest:
SELECT DAY(EOMONTH(GETDATE()))
This code gets you the number of days in current month:
SELECT datediff(dd,getdate(),dateadd(mm,1,getdate())) as datas
Change getdate() to the date you need to count days for.
--- sql server below 2012---
select day( dateadd(day,-1,dateadd(month, 1, convert(date,'2019-03-01'))))
-- this for sql server 2012--
select day(EOMONTH(getdate()))
Solution 1: Find the number of days in whatever month we're currently in
DECLARE #dt datetime
SET #dt = getdate()
SELECT #dt AS [DateTime],
DAY(DATEADD(mm, DATEDIFF(mm, -1, #dt), -1)) AS [Days in Month]
Solution 2: Find the number of days in a given month-year combo
DECLARE #y int, #m int
SET #y = 2012
SET #m = 2
SELECT #y AS [Year],
#m AS [Month],
DATEDIFF(DAY,
DATEADD(DAY, 0, DATEADD(m, ((#y - 1900) * 12) + #m - 1, 0)),
DATEADD(DAY, 0, DATEADD(m, ((#y - 1900) * 12) + #m, 0))
) AS [Days in Month]
You do need to add a function, but it's a simple one. I use this:
CREATE FUNCTION [dbo].[ufn_GetDaysInMonth] ( #pDate DATETIME )
RETURNS INT
AS
BEGIN
SET #pDate = CONVERT(VARCHAR(10), #pDate, 101)
SET #pDate = #pDate - DAY(#pDate) + 1
RETURN DATEDIFF(DD, #pDate, DATEADD(MM, 1, #pDate))
END
GO
SELECT Datediff(day,
(Convert(DateTime,Convert(varchar(2),Month(getdate()))+'/01/'+Convert(varchar(4),Year(getdate())))),
(Convert(DateTime,Convert(varchar(2),Month(getdate())+1)+'/01/'+Convert(varchar(4),Year(getdate()))))) as [No.of Days in a Month]
select datediff(day,
dateadd(day, 0, dateadd(month, ((2013 - 1900) * 12) + 3 - 1, 0)),
dateadd(day, 0, dateadd(month, ((2013 - 1900) * 12) + 3, 0))
)
Nice Simple and does not require creating any functions Work Fine
You need to create a function, but it is for your own convenience. It works perfect and I never encountered any faulty computations using this function.
CREATE FUNCTION [dbo].[get_days](#date datetime)
RETURNS int
AS
BEGIN
SET #date = DATEADD(MONTH, 1, #date)
DECLARE #result int = (select DAY(DATEADD(DAY, -DAY(#date), #date)))
RETURN #result
END
How it works: subtracting the date's day number from the date itself gives you the last day of previous month. So, you need to add one month to the given date, subtract the day number and get the day component of the result.
select add_months(trunc(sysdate,'MM'),1) - trunc(sysdate,'MM') from dual;
I upvoted Mehrdad, but this works as well. :)
CREATE function dbo.IsLeapYear
(
#TestYear int
)
RETURNS bit
AS
BEGIN
declare #Result bit
set #Result =
cast(
case when ((#TestYear % 4 = 0) and (#testYear % 100 != 0)) or (#TestYear % 400 = 0)
then 1
else 0
end
as bit )
return #Result
END
GO
CREATE FUNCTION dbo.GetDaysInMonth
(
#TestDT datetime
)
RETURNS INT
AS
BEGIN
DECLARE #Result int
DECLARE #MonthNo int
Set #MonthNo = datepart(m,#TestDT)
Set #Result =
case #MonthNo
when 1 then 31
when 2 then
case
when dbo.IsLeapYear(datepart(yyyy,#TestDT)) = 0
then 28
else 29
end
when 3 then 31
when 4 then 30
when 5 then 31
when 6 then 30
when 7 then 31
when 8 then 31
when 9 then 30
when 10 then 31
when 11 then 30
when 12 then 31
end
RETURN #Result
END
GO
To Test
declare #testDT datetime;
set #testDT = '2404-feb-15';
select dbo.GetDaysInMonth(#testDT)
here's another one...
Select Day(DateAdd(day, -Day(DateAdd(month, 1, getdate())),
DateAdd(month, 1, getdate())))
I know this question is old but I thought I would share what I'm using.
DECLARE #date date = '2011-12-22'
/* FindFirstDayOfMonth - Find the first date of any month */
-- Replace the day part with -01
DECLARE #firstDayOfMonth date = CAST( CAST(YEAR(#date) AS varchar(4)) + '-' +
CAST(MONTH(#date) AS varchar(2)) + '-01' AS date)
SELECT #firstDayOfMonth
and
DECLARE #date date = '2011-12-22'
/* FindLastDayOfMonth - Find what is the last day of a month - Leap year is handled by DATEADD */
-- Get the first day of next month and remove a day from it using DATEADD
DECLARE #lastDayOfMonth date = CAST( DATEADD(dd, -1, DATEADD(mm, 1, FindFirstDayOfMonth(#date))) AS date)
SELECT #lastDayOfMonth
Those could be combine to create a single function to retrieve the number of days in a month if needed.
SELECT DAY(SUBDATE(ADDDATE(CONCAT(YEAR(NOW()), '-', MONTH(NOW()), '-1'), INTERVAL 1 MONTH), INTERVAL 1 DAY))
Nice 'n' Simple and does not require creating any functions
Mehrdad Afshari reply is most accurate one, apart from usual this answer is based on formal mathematical approach given by Curtis McEnroe in his blog https://cmcenroe.me/2014/12/05/days-in-month-formula.html
DECLARE #date DATE= '2015-02-01'
DECLARE #monthNumber TINYINT
DECLARE #dayCount TINYINT
SET #monthNumber = DATEPART(MONTH,#date )
SET #dayCount = 28 + (#monthNumber + floor(#monthNumber/8)) % 2 + 2 % #monthNumber + 2 * floor(1/#monthNumber)
SELECT #dayCount + CASE WHEN #dayCount = 28 AND DATEPART(YEAR,#date)%4 =0 THEN 1 ELSE 0 END -- leap year adjustment
To get the no. of days in a month we can directly use Day() available in SQL.
Follow the link posted at the end of my answer for SQL Server 2005 / 2008.
The following example and the result are from SQL 2012
alter function dbo.[daysinm]
(
#dates nvarchar(12)
)
returns int
as
begin
Declare #dates2 nvarchar(12)
Declare #days int
begin
select #dates2 = (select DAY(EOMONTH(convert(datetime,#dates,103))))
set #days = convert(int,#dates2)
end
return #days
end
--select dbo.daysinm('08/12/2016')
Result in SQL Server SSMS
(no column name)
1 31
Process:
When EOMONTH is used, whichever the date format we use it is converted into DateTime format of SQL-server. Then the date output of EOMONTH() will be 2016-12-31 having 2016 as Year, 12 as Month and 31 as Days.
This output when passed into Day() it gives you the total days count in the month.
If we want to get the instant result for checking we can directly run the below code,
select DAY(EOMONTH(convert(datetime,'08/12/2016',103)))
or
select DAY(EOMONTH(convert(datetime,getdate(),103)))
for reference to work in SQL Server 2005/2008/2012, please follow the following external link ...
Find No. of Days in a Month in SQL
DECLARE #date DATETIME = GETDATE(); --or '12/1/2018' (month/day/year)
SELECT DAY(EOMONTH ( #date )) AS 'This Month';
SELECT DAY(EOMONTH ( #date, 1 )) AS 'Next Month';
result:
This Month
31
Next Month
30
DECLARE #m int
SET #m = 2
SELECT
#m AS [Month],
DATEDIFF(DAY,
DATEADD(DAY, 0, DATEADD(m, +#m -1, 0)),
DATEADD(DAY, 0, DATEADD(m,+ #m, 0))
) AS [Days in Month]
RETURN day(dateadd(month, 12 * #year + #month - 22800, -1))
select day(dateadd(month, 12 * year(date) + month(date) - 22800, -1))
A cleaner way of implementing this is using the datefromparts function to construct the first day of the month, and calculate the days from there.
CREATE FUNCTION [dbo].[fn_DaysInMonth]
(
#year INT,
#month INT
)
RETURNS INT
AS
BEGIN
IF #month < 1 OR #month > 12 RETURN NULL;
IF #year < 1753 OR #year > 9998 RETURN NULL;
DECLARE #firstDay DATE = datefromparts(#year, #month, 1);
DECLARE #lastDay DATE = dateadd(month, 1, #firstDay);
RETURN datediff(day, #firstDay, #lastDay);
END
GO
Similarily, you can calculate the days in a year:
CREATE FUNCTION [dbo].[fn_DaysInYear]
(
#year INT
)
RETURNS INT
AS
BEGIN
IF #year < 1753 OR #year > 9998 RETURN NULL;
DECLARE #firstDay DATE = datefromparts(#year, 1, 1);
DECLARE #lastDay DATE = dateadd(year, 1, #firstDay);
RETURN datediff(day, #firstDay, #lastDay);
END
GO
use SQL Server EOMONTH Function nested with day to get last day of month
select Day(EOMONTH('2020-02-1')) -- Leap Year returns 29
select Day(EOMONTH('2021-02-1')) -- returns 28
select Day(EOMONTH('2021-03-1')) -- returns 31
For any date
select DateDiff(Day,#date,DateAdd(month,1,#date))
select first_day=dateadd(dd,-1*datepart(dd,getdate())+1,getdate()),
last_day=dateadd(dd,-1*datepart(dd,dateadd(mm,1,getdate())),dateadd(mm,1,getdate())),
no_of_days = 1+datediff(dd,dateadd(dd,-1*datepart(dd,getdate())+1,getdate()),dateadd(dd,-1*datepart(dd,dateadd(mm,1,getdate())),dateadd(mm,1,getdate())))
replace any date with getdate to get the no of months in that particular date
DECLARE #Month INT=2,
#Year INT=1989
DECLARE #date DateTime=null
SET #date=CAST(CAST(#Year AS nvarchar) + '-' + CAST(#Month AS nvarchar) + '-' + '1' AS DATETIME);
DECLARE #noofDays TINYINT
DECLARE #CountForDate TINYINT
SET #noofDays = DATEPART(MONTH,#date )
SET #CountForDate = 28 + (#noofDays + floor(#noofDays/8)) % 2 + 2 % #noofDays + 2 * floor(1/#noofDays)
SET #noofDays= #CountForDate + CASE WHEN #CountForDate = 28 AND DATEPART(YEAR,#date)%4 =0 THEN 1 ELSE 0 END
PRINT #noofDays
DECLARE #date nvarchar(20)
SET #date ='2012-02-09 00:00:00'
SELECT DATEDIFF(day,cast(replace(cast(YEAR(#date) as char)+'-'+cast(MONTH(#date) as char)+'-01',' ','')+' 00:00:00' as datetime),dateadd(month,1,cast(replace(cast(YEAR(#date) as char)+'-'+cast(MONTH(#date) as char)+'-01',' ','')+' 00:00:00' as datetime)))
simple query in SQLServer2012 :
select day(('20-05-1951 22:00:00'))
i tested for many dates and it return always a correct result