13 Period Calendar 4-4-5 Calendar T-SQL MSSQL - sql-server

Question

I am trying to create a 13 period calendar in mssql but I am a bit stuck. I am not sure if my approach is the best way to achieve this. I have my base script which can be seen below:
Set DateFirst 1
Declare #Date1 date = '20180101' --startdate should always be start of
financial year
Declare #Date2 date = '20181231' --enddate should always be start of
financial year
SELECT * INTO #CalendarTable
FROM dbo.CalendarTable(#Date1,#Date2,0,0,0)c
DECLARE #StartDate datetime,#EndDate datetime
SELECT #StartDate=MIN(CASE WHEN [Day]='Monday' THEN [Date] ELSE NULL END),
#EndDate=MAX([Date])
FROM #CalendarTable
;With Period_CTE(PeriodNo,Start,[End])
AS
(SELECT 1,#StartDate,DATEADD(wk,4,#StartDate) -1
UNION ALL
SELECT PeriodNo+1,DATEADD(wk,4,Start),DATEADD(wk,4,[End])
FROM Period_CTE
WHERE DATEADD(wk,4,[End])< =#EndDate
OR PeriodNo+1 <=13
)
select * from Period_CTE
Which gives me this:
PeriodNo Start End
1 2018-01-01 00:00:00.000 2018-01-28 00:00:00.000
2 2018-01-29 00:00:00.000 2018-02-25 00:00:00.000
3 2018-02-26 00:00:00.000 2018-03-25 00:00:00.000
4 2018-03-26 00:00:00.000 2018-04-22 00:00:00.000
5 2018-04-23 00:00:00.000 2018-05-20 00:00:00.000
6 2018-05-21 00:00:00.000 2018-06-17 00:00:00.000
7 2018-06-18 00:00:00.000 2018-07-15 00:00:00.000
8 2018-07-16 00:00:00.000 2018-08-12 00:00:00.000
9 2018-08-13 00:00:00.000 2018-09-09 00:00:00.000
10 2018-09-10 00:00:00.000 2018-10-07 00:00:00.000
11 2018-10-08 00:00:00.000 2018-11-04 00:00:00.000
12 2018-11-05 00:00:00.000 2018-12-02 00:00:00.000
13 2018-12-03 00:00:00.000 2018-12-30 00:00:00.000
The result i am trying to get is
Even if I have to take a different approach I would not mind, as long as the result is the same as the above.
dbo.CalendarTable() is a function that returns the following results. I can share the code if desired.

Answer 1

I'd create a general number's table like suggested here and add a column Periode13.
The trick to get the tiling is the integer division:
DECLARE #PeriodeSize INT=28; --13 "moon-months" a 28 days
SELECT TOP 100 (ROW_NUMBER() OVER(ORDER BY (SELECT NULL))-1)/#PeriodeSize
FROM master..spt_values --just a table with many rows to show the principles
You can add this to an existing numbers table with a simple update statement.
UPDATE A fully working example (using the logic linked above)
DECLARE #RunningNumbers TABLE (Number INT NOT NULL
,CalendarDate DATE NOT NULL
,CalendarYear INT NOT NULL
,CalendarMonth INT NOT NULL
,CalendarDay INT NOT NULL
,CalendarWeek INT NOT NULL
,CalendarYearDay INT NOT NULL
,CalendarWeekDay INT NOT NULL);
DECLARE #CountEntries INT = 100000;
DECLARE #StartNumber INT = 0;
WITH E1(N) AS(SELECT 1 FROM(VALUES (1),(1),(1),(1),(1),(1),(1),(1),(1),(1))t(N)), --10 ^ 1
E2(N) AS(SELECT 1 FROM E1 a CROSS JOIN E1 b), -- 10 ^ 2 = 100 rows
E4(N) AS(SELECT 1 FROM E2 a CROSS JOIN E2 b), -- 10 ^ 4 = 10,000 rows
E8(N) AS(SELECT 1 FROM E4 a CROSS JOIN E4 b), -- 10 ^ 8 = 10,000,000 rows
CteTally AS
(
SELECT TOP(ISNULL(#CountEntries,1000000)) ROW_NUMBER() OVER(ORDER BY(SELECT NULL)) -1 + ISNULL(#StartNumber,0) As Nmbr
FROM E8
)
INSERT INTO #RunningNumbers
SELECT CteTally.Nmbr,CalendarDate.d,CalendarExt.*
FROM CteTally
CROSS APPLY
(
SELECT DATEADD(DAY,CteTally.Nmbr,{ts'2018-01-01 00:00:00'})
) AS CalendarDate(d)
CROSS APPLY
(
SELECT YEAR(CalendarDate.d) AS CalendarYear
,MONTH(CalendarDate.d) AS CalendarMonth
,DAY(CalendarDate.d) AS CalendarDay
,DATEPART(WEEK,CalendarDate.d) AS CalendarWeek
,DATEPART(DAYOFYEAR,CalendarDate.d) AS CalendarYearDay
,DATEPART(WEEKDAY,CalendarDate.d) AS CalendarWeekDay
) AS CalendarExt;
--The mockup table from above is now filled and can be queried
WITH AddPeriode AS
(
SELECT Number/28 +1 AS PeriodNumber
,CalendarDate
,CalendarWeek
,r.CalendarDay
,r.CalendarMonth
,r.CalendarWeekDay
,r.CalendarYear
,r.CalendarYearDay
FROM #RunningNumbers AS r
)
SELECT TOP 100 p.*
,(SELECT MIN(CalendarDate) FROM AddPeriode AS x WHERE x.PeriodNumber=p.PeriodNumber) AS [Start]
,(SELECT MAX(CalendarDate) FROM AddPeriode AS x WHERE x.PeriodNumber=p.PeriodNumber) AS [End]
,(SELECT MIN(CalendarDate) FROM AddPeriode AS x WHERE x.PeriodNumber=p.PeriodNumber AND x.CalendarWeek=p.CalendarWeek) AS [wkStart]
,(SELECT MAX(CalendarDate) FROM AddPeriode AS x WHERE x.PeriodNumber=p.PeriodNumber AND x.CalendarWeek=p.CalendarWeek) AS [wkEnd]
,(ROW_NUMBER() OVER(PARTITION BY PeriodNumber ORDER BY CalendarDate)-1)/7+1 AS WeekOfPeriode
FROM AddPeriode AS p
ORDER BY CalendarDate
Try it out...
Hint: Do not use a VIEW or iTVF for this.
This is non-changing data and much better placed in a physically stored table with appropriate indexes.

Answer 2

Not abundantly sure external links are accepted here, but I wrote an article that pulls of a 5-4-4 'Crop Year' fiscal year with all the code. Feel free to use all the code in these articles.
SQL Server Calendar Table
SQL Server Calendar Table: Fiscal Years