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 Topic  |
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Michael Valentine Jones
Yak DBA Kernel (pronounced Colonel)
USA
6997 Posts |
 Posted - 01/18/2006 : 22:08:27
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Function F_ISO_YEAR_WEEK_DAY_OF_WEEK returns the ISO 8601 Year Week Day of Week in format YYYY-W01-D for the date passed. W01 represents the week of the year from W01 through W53, and D represents the day of the week with 1 = Monday through 7 = Sunday.
The first week of each year starts on the first Monday on or before January 4 of that year, so that the year begins from December 28 of the prior year through January 4 of the current year.
This code creates the function and demos it for the first day, first date+60, and first date+364 for each ISO week/year from 1990 to 2030.
drop function dbo.F_ISO_YEAR_WEEK_DAY_OF_WEEK
GO
create function dbo.F_ISO_YEAR_WEEK_DAY_OF_WEEK
(
@Date datetime
)
returns varchar(10)
as
/*
Function F_ISO_YEAR_WEEK_DAY_OF_WEEK
returns the ISO 8601 Year Week Day of Week
in format YYYY-W01-D for the date passed.
*/
begin
declare @YearWeekDayOfWeek varchar(10)
Select
--Format to form YYYY-W01-D
@YearWeekDayOfWeek =
convert(varchar(4),year(dateadd(dd,7,a.YearStart)))+'-W'+
right('00'+convert(varchar(2),(datediff(dd,a.YearStart,@Date)/7)+1),2) +
'-'+convert(varchar(1),(datediff(dd,a.YearStart,@Date)%7)+1)
from
(
select
YearStart =
-- Case finds start of year
case
when NextYrStart <= @date
then NextYrStart
when CurrYrStart <= @date
then CurrYrStart
else PriorYrStart
end
from
(
select
-- First day of first week of prior year
PriorYrStart =
dateadd(dd,(datediff(dd,-53690,dateadd(yy,-1,aaa.Jan4))/7)*7,-53690),
-- First day of first week of current year
CurrYrStart =
dateadd(dd,(datediff(dd,-53690,aaa.Jan4)/7)*7,-53690),
-- First day of first week of next year
NextYrStart =
dateadd(dd,(datediff(dd,-53690,dateadd(yy,1,aaa.Jan4))/7)*7,-53690)
from
(
select
--Find Jan 4 for the year of the input date
Jan4 =
dateadd(dd,3,dateadd(yy,datediff(yy,0,@date),0))
) aaa
) aa
) a
return @YearWeekDayOfWeek
end
go
-- Execute function on first day, first day+60,
-- and first day+364 for years from 1990 to 2030.
select
DT = convert(varchar(10),DT,121),
YR_START_DT =
dbo.F_ISO_YEAR_WEEK_DAY_OF_WEEK(a.DT),
YR_START_DT_60 =
dbo.F_ISO_YEAR_WEEK_DAY_OF_WEEK(a.DT+60),
YR_START_DT_365 =
dbo.F_ISO_YEAR_WEEK_DAY_OF_WEEK(a.DT+364)
from
(
select DT = getdate() union all
select DT = convert(datetime,'1990/01/01') union all
select DT = convert(datetime,'1990/12/31') union all
select DT = convert(datetime,'1991/12/30') union all
select DT = convert(datetime,'1993/01/04') union all
select DT = convert(datetime,'1994/01/03') union all
select DT = convert(datetime,'1995/01/02') union all
select DT = convert(datetime,'1996/01/01') union all
select DT = convert(datetime,'1996/12/30') union all
select DT = convert(datetime,'1997/12/29') union all
select DT = convert(datetime,'1999/01/04') union all
select DT = convert(datetime,'2000/01/03') union all
select DT = convert(datetime,'2001/01/01') union all
select DT = convert(datetime,'2001/12/31') union all
select DT = convert(datetime,'2002/12/30') union all
select DT = convert(datetime,'2003/12/29') union all
select DT = convert(datetime,'2005/01/03') union all
select DT = convert(datetime,'2006/01/02') union all
select DT = convert(datetime,'2007/01/01') union all
select DT = convert(datetime,'2007/12/31') union all
select DT = convert(datetime,'2008/12/29') union all
select DT = convert(datetime,'2010/01/04') union all
select DT = convert(datetime,'2011/01/03') union all
select DT = convert(datetime,'2012/01/02') union all
select DT = convert(datetime,'2012/12/31') union all
select DT = convert(datetime,'2013/12/30') union all
select DT = convert(datetime,'2014/12/29') union all
select DT = convert(datetime,'2016/01/04') union all
select DT = convert(datetime,'2017/01/02') union all
select DT = convert(datetime,'2018/01/01') union all
select DT = convert(datetime,'2018/12/31') union all
select DT = convert(datetime,'2019/12/30') union all
select DT = convert(datetime,'2021/01/04') union all
select DT = convert(datetime,'2022/01/03') union all
select DT = convert(datetime,'2023/01/02') union all
select DT = convert(datetime,'2024/01/01') union all
select DT = convert(datetime,'2024/12/30') union all
select DT = convert(datetime,'2025/12/29') union all
select DT = convert(datetime,'2027/01/04') union all
select DT = convert(datetime,'2028/01/03') union all
select DT = convert(datetime,'2029/01/01') union all
select DT = convert(datetime,'2029/12/31') union all
select DT = convert(datetime,'2030/12/30')
) a
Function Test Results:
DT YR_START_DT YR_START_DT_60 YR_START_DT_364
---------- ----------- -------------- ---------------
2006-01-18 2006-W03-3 2006-W11-7 2007-W03-3
1990-01-01 1990-W01-1 1990-W09-5 1991-W01-1
1990-12-31 1991-W01-1 1991-W09-5 1992-W01-1
1991-12-30 1992-W01-1 1992-W09-5 1992-W53-1
1993-01-04 1993-W01-1 1993-W09-5 1994-W01-1
1994-01-03 1994-W01-1 1994-W09-5 1995-W01-1
1995-01-02 1995-W01-1 1995-W09-5 1996-W01-1
1996-01-01 1996-W01-1 1996-W09-5 1997-W01-1
1996-12-30 1997-W01-1 1997-W09-5 1998-W01-1
1997-12-29 1998-W01-1 1998-W09-5 1998-W53-1
1999-01-04 1999-W01-1 1999-W09-5 2000-W01-1
2000-01-03 2000-W01-1 2000-W09-5 2001-W01-1
2001-01-01 2001-W01-1 2001-W09-5 2002-W01-1
2001-12-31 2002-W01-1 2002-W09-5 2003-W01-1
2002-12-30 2003-W01-1 2003-W09-5 2004-W01-1
2003-12-29 2004-W01-1 2004-W09-5 2004-W53-1
2005-01-03 2005-W01-1 2005-W09-5 2006-W01-1
2006-01-02 2006-W01-1 2006-W09-5 2007-W01-1
2007-01-01 2007-W01-1 2007-W09-5 2008-W01-1
2007-12-31 2008-W01-1 2008-W09-5 2009-W01-1
2008-12-29 2009-W01-1 2009-W09-5 2009-W53-1
2010-01-04 2010-W01-1 2010-W09-5 2011-W01-1
2011-01-03 2011-W01-1 2011-W09-5 2012-W01-1
2012-01-02 2012-W01-1 2012-W09-5 2013-W01-1
2012-12-31 2013-W01-1 2013-W09-5 2014-W01-1
2013-12-30 2014-W01-1 2014-W09-5 2015-W01-1
2014-12-29 2015-W01-1 2015-W09-5 2015-W53-1
2016-01-04 2016-W01-1 2016-W09-5 2017-W01-1
2017-01-02 2017-W01-1 2017-W09-5 2018-W01-1
2018-01-01 2018-W01-1 2018-W09-5 2019-W01-1
2018-12-31 2019-W01-1 2019-W09-5 2020-W01-1
2019-12-30 2020-W01-1 2020-W09-5 2020-W53-1
2021-01-04 2021-W01-1 2021-W09-5 2022-W01-1
2022-01-03 2022-W01-1 2022-W09-5 2023-W01-1
2023-01-02 2023-W01-1 2023-W09-5 2024-W01-1
2024-01-01 2024-W01-1 2024-W09-5 2025-W01-1
2024-12-30 2025-W01-1 2025-W09-5 2026-W01-1
2025-12-29 2026-W01-1 2026-W09-5 2026-W53-1
2027-01-04 2027-W01-1 2027-W09-5 2028-W01-1
2028-01-03 2028-W01-1 2028-W09-5 2029-W01-1
2029-01-01 2029-W01-1 2029-W09-5 2030-W01-1
2029-12-31 2030-W01-1 2030-W09-5 2031-W01-1
2030-12-30 2031-W01-1 2031-W09-5 2032-W01-1
(43 row(s) affected)
CODO ERGO SUM |
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evbstv
Starting Member
2 Posts |
Posted - 03/19/2008 : 15:57:56
|
| Great! I searched other places for this but this is the best one of all. Thanks. |
 |
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Lxocram
Starting Member
Belgium
1 Posts |
Posted - 02/03/2012 : 07:53:31
|
The test-code is not language setting proof, add conversion hint ,121
Msg 242, Level 16, State 3, Line 6
The conversion of a char data type to a datetime data type resulted in an out-of-range datetime value.
-- Execute function on first day, first day+60,
-- and first day+364 for years from 1990 to 2030.
select
DT = convert(varchar(10),DT,121),
YR_START_DT =
dbo.F_ISO_YEAR_WEEK_DAY_OF_WEEK(a.DT),
YR_START_DT_60 =
dbo.F_ISO_YEAR_WEEK_DAY_OF_WEEK(a.DT+60),
YR_START_DT_365 =
dbo.F_ISO_YEAR_WEEK_DAY_OF_WEEK(a.DT+364)
from
(
select DT = getdate() union all
select DT = convert(datetime,'1990/01/01',121) union all
select DT = convert(datetime,'1990/12/31',121) union all
select DT = convert(datetime,'1991/12/30',121) union all
select DT = convert(datetime,'1993/01/04',121) union all
select DT = convert(datetime,'1994/01/03',121) union all
select DT = convert(datetime,'1995/01/02',121) union all
select DT = convert(datetime,'1996/01/01',121) union all
select DT = convert(datetime,'1996/12/30',121) union all
select DT = convert(datetime,'1997/12/29',121) union all
select DT = convert(datetime,'1999/01/04',121) union all
select DT = convert(datetime,'2000/01/03',121) union all
select DT = convert(datetime,'2001/01/01',121) union all
select DT = convert(datetime,'2001/12/31',121) union all
select DT = convert(datetime,'2002/12/30',121) union all
select DT = convert(datetime,'2003/12/29',121) union all
select DT = convert(datetime,'2005/01/03',121) union all
select DT = convert(datetime,'2006/01/02',121) union all
select DT = convert(datetime,'2007/01/01',121) union all
select DT = convert(datetime,'2007/12/31',121) union all
select DT = convert(datetime,'2008/12/29',121) union all
select DT = convert(datetime,'2010/01/04',121) union all
select DT = convert(datetime,'2011/01/03',121) union all
select DT = convert(datetime,'2012/01/02',121) union all
select DT = convert(datetime,'2012/12/31',121) union all
select DT = convert(datetime,'2013/12/30',121) union all
select DT = convert(datetime,'2014/12/29',121) union all
select DT = convert(datetime,'2016/01/04',121) union all
select DT = convert(datetime,'2017/01/02',121) union all
select DT = convert(datetime,'2018/01/01',121) union all
select DT = convert(datetime,'2018/12/31',121) union all
select DT = convert(datetime,'2019/12/30',121) union all
select DT = convert(datetime,'2021/01/04',121) union all
select DT = convert(datetime,'2022/01/03',121) union all
select DT = convert(datetime,'2023/01/02',121) union all
select DT = convert(datetime,'2024/01/01',121) union all
select DT = convert(datetime,'2024/12/30',121) union all
select DT = convert(datetime,'2025/12/29',121) union all
select DT = convert(datetime,'2027/01/04',121) union all
select DT = convert(datetime,'2028/01/03',121) union all
select DT = convert(datetime,'2029/01/01',121) union all
select DT = convert(datetime,'2029/12/31',121) union all
select DT = convert(datetime,'2030/12/30',121)
) a
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Topic |
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ISO Year Week Day of Week Function
