DATEINT
Updated: 07 February 2011
Use DATEINT to return an int value for a specified Year, Month, and Day. DATEINT is the equivalent of the DATE function in EXCEL.
Syntax
SELECT [wctFinancial].[wct].[DATEINT](
<@Year, int,>
,<@Month, int,>
,<@Day, int,>)
Arguments
@Year
The integer value representing the year. @Year is an expression that returns an int or that can be implicitly converted to int.
@Month
The integer value representing the month. @Month is an expression that returns an int or that can be implicitly converted to int.
@Day
The integer value representing the day of the month. @Day is an expression that returns an int or that can be implicitly converted to int.
Return Type
int
Remarks
· DATEINT is the equivalent of the DATE function in EXCEL, except that it returns an integer representing the number of days from 01-Jan-1900. This is consistent with numeric representation of dates in SQL Server. EXCEL and .NET have different numeric representations of dates than SQL Server.
· To convert a year, month, and day combination to a datetime, consider using the CALCDATE function.
· To convert a year, month, and day combination to a float, consider using the DATEFLOAT function.
Examples
To represent 07-Feb-2011, enter the following SQL.
SELECT wct.DATEINT(
2011 --@Year
,2 --@Month
,7 --@Day
) as DATEINT
This produces the following result.
DATEINT
-----------
40579
(1 row(s) affected)
DATEINT is language independent. The datetime value returned is consistent across different language settings. Look at the following example.
SET LANGUAGE Italian
SELECT wct.DATEINT(2011,2,7) as [DATEINT(2011,2,7)]
,cast(cast('02/07/2011' as datetime) as int) as [cast(cast('02/07/2011' as datetime) as int)]
This returns the following result.
DATEINT(2011,2,7) cast(cast('02/07/2011' as datetime) as int)
----------------- -------------------------------------------
40579 40724
(1 row(s) affected)
SET LANGUAGE us_english
SELECT wct.DATEINT(2011,2,7) as [DATEINT(2011,2,7)]
,cast(cast('02/07/2011' as datetime) as int) as [cast(cast('02/07/2011' as datetime) as int)]
This returns the following result
DATEINT(2011,2,7) cast(cast('02/07/2011' as datetime) as int)
----------------- -------------------------------------------
40579 40579
(1 row(s) affected)
As you can see,the same date string was passed in both statements, but the datetime value returned was different based upon the language setting for the database. Using DATEINT avoids that problem.
DATEINT allows you to perform operation on the date components. You can add or subtract integer values to @Year, @Month, @Date, and still be confident of having a valid value returned.
Let’s say you wanted to generate a schedule that showed the first Monday of every month. Here’s one way to do this in SQL.
SELECT DATEADD(d
,(9 - DATEPART(DW,
cast(
cast(mth as varchar) + '/1/' + cast(2011 as varchar)
as datetime
)
)
) % 7
,cast(
cast(mth as varchar) + '/1/' + cast(2011 as varchar)
as datetime
)
) as [First Monday]
FROM (
VALUES
(1), (2), (3), (4), (5), (6),
(7), (8), (9), (10), (11), (12)
) m(mth)
This produces the following result.
First Monday
-----------------------
2011-01-03 00:00:00.000
2011-02-07 00:00:00.000
2011-03-07 00:00:00.000
2011-04-04 00:00:00.000
2011-05-02 00:00:00.000
2011-06-06 00:00:00.000
2011-07-04 00:00:00.000
2011-08-01 00:00:00.000
2011-09-05 00:00:00.000
2011-10-03 00:00:00.000
2011-11-07 00:00:00.000
2011-12-05 00:00:00.000
(12 row(s) affected)
DATEINT allows you to perform operations on the components of the date rather than on the date value, simplifying the SQL.
SELECT CAST(wct.DATEINT(2011
,mth
,1 +(9 - DATEPART(DW,wct.DATEINT(2011,mth,1))) % 7
) as datetime) as [First Monday]
FROM (
VALUES
(1),(2),(3),(4),(5),(6),
(7),(8),(9),(10),(11),(12)
) m(mth)
This produces the following result.
First Monday
-----------------------
2011-01-03 00:00:00.000
2011-02-07 00:00:00.000
2011-03-07 00:00:00.000
2011-04-04 00:00:00.000
2011-05-02 00:00:00.000
2011-06-06 00:00:00.000
2011-07-04 00:00:00.000
2011-08-01 00:00:00.000
2011-09-05 00:00:00.000
2011-10-03 00:00:00.000
2011-11-07 00:00:00.000
2011-12-05 00:00:00.000
(12 row(s) affected)
As a side note, the reason that we used 9 to represent Monday and did not use 2 in this SQL (2 being the numeric representation of Monday), is that the modulo function, %, in SQL Server is really a remainder function. The SQL would look more intuitive if we had used the XLeratorDB modulo function (which is the equivalent of the EXCEL MOD function).SELECT CAST(wct.DATEINT(2011
,mth
,1 + wct.Modulo(
(2 - DATEPART(DW,wct.DATEINT(2011,mth,1)))
,7)
) as datetime) as [First Monday]
FROM (
VALUES
(1),(2),(3),(4),(5),(6),
(7),(8),(9),(10),(11),(12)
) m(mth)
This produces the following result.
First Monday
-----------------------
2011-01-03 00:00:00.000
2011-02-07 00:00:00.000
2011-03-07 00:00:00.000
2011-04-04 00:00:00.000
2011-05-02 00:00:00.000
2011-06-06 00:00:00.000
2011-07-04 00:00:00.000
2011-08-01 00:00:00.000
2011-09-05 00:00:00.000
2011-10-03 00:00:00.000
2011-11-07 00:00:00.000
2011-12-05 00:00:00.000
(12 row(s) affected)
DATEINT can simplify date calculations on the database. Let’s say that you are a company that has a 52-53 week fiscal year, and the year end is defined as the final Saturday in the year end month. You need to calculate the year end date and the number of days in the year.
DECLARE @YEM as int = 8
SELECT yr
,CAST([Last Saturday] as datetime) as [Last Saturday]
,[Last Saturday] - [Last Saturday PY] as [Days in Year]
FROM(
SELECT yr
,wct.DATEINT(yr, @YEM,DATEPART(d,wct.DATEINT(yr, @YEM+1, 1)-7) + wct.Modulo((7 - DATEPART(DW,wct.DATEINT(yr, @YEM+1, 1)-7)),7)) as [Last Saturday]
,wct.DATEINT(yr-1, @YEM,DATEPART(d,wct.DATEINT(yr-1, @YEM+1, 1)-7) + westclintech.wct.Modulo((7 - DATEPART(DW,wct.DATEINT(yr-1, @YEM+1, 1)-7)),7)) as [Last Saturday PY]
FROM (
VALUES
(2005),(2006),(2007),(2008),(2009),
(2010),(2011),(2012),(2013),(2014),
(2015),(2016),(2017),(2018),(2019)
) n(yr)
) m
This produces the following result
yr Last Saturday Days in Year
----------- ----------------------- ------------
2005 2005-08-27 00:00:00.000 364
2006 2006-08-26 00:00:00.000 364
2007 2007-08-25 00:00:00.000 364
2008 2008-08-30 00:00:00.000 371
2009 2009-08-29 00:00:00.000 364
2010 2010-08-28 00:00:00.000 364
2011 2011-08-27 00:00:00.000 364
2012 2012-08-25 00:00:00.000 364
2013 2013-08-31 00:00:00.000 371
2014 2014-08-30 00:00:00.000 364
2015 2015-08-29 00:00:00.000 364
2016 2016-08-27 00:00:00.000 364
2017 2017-08-26 00:00:00.000 364
2018 2018-08-25 00:00:00.000 364
2019 2019-08-31 00:00:00.000 371
(15 row(s) affected)
In this example the year end date is the Saturday that falls closest to the last day of the fiscal year end month.
DECLARE @YEM as int = 8
SELECT yr
,CAST(YE as datetime) as [YE Date]
,YE - PYE as [Days in Year]
FROM (
SELECT yr
,wct.DATEINT(yr, @YEM,DATEPART(d,wct.DATEINT(yr, @YEM+1, 1)-4) + wct.Modulo((7 - DATEPART(DW,wct.DATEINT(yr, @YEM+1, 1)-4)),7)) as YE
,wct.DATEINT(yr-1, @YEM,DATEPART(d,wct.DATEINT(yr-1, @YEM+1, 1)-4) + wct.Modulo((7 - DATEPART(DW,wct.DATEINT(yr-1, @YEM+1, 1)-4)),7)) as PYE
FROM (
VALUES
(2005),(2006),(2007),(2008),(2009),
(2010),(2011),(2012),(2013),(2014),
(2015),(2016),(2017),(2018),(2019)
) n(yr)
) m
This produces the following result.
yr YE Date Days in Year
----------- ----------------------- ------------
2005 2005-09-03 00:00:00.000 371
2006 2006-09-02 00:00:00.000 364
2007 2007-09-01 00:00:00.000 364
2008 2008-08-30 00:00:00.000 364
2009 2009-08-29 00:00:00.000 364
2010 2010-08-28 00:00:00.000 364
2011 2011-09-03 00:00:00.000 371
2012 2012-09-01 00:00:00.000 364
2013 2013-08-31 00:00:00.000 364
2014 2014-08-30 00:00:00.000 364
2015 2015-08-29 00:00:00.000 364
2016 2016-09-03 00:00:00.000 371
2017 2017-09-02 00:00:00.000 364
2018 2018-09-01 00:00:00.000 364
2019 2019-08-31 00:00:00.000 364
(15 row(s) affected)