Count of weekdays in a given month - sql

I was facing a problem on how to create a calculated column based on a column which contains dates. For example, I have a column which contains dates starting from July.
The DAY needs to be calculated as described in the picture using SQL server.
So basically can a column be created based on an existing column containing a lot of dates? I need this to be dynamic.
WeekDay Date Day
---------------------------
Friday 3-Jan-14 1
Monday 6-Jan-14 2
Tuesday 7-Jan-14 3
Wednesday 8-Jan-14 4
Thursday 9-Jan-14 5
Friday 10-Jan-14 6
Monday 13-Jan-14 7
Tuesday 14-Jan-14 8
Wednesday 15-Jan-14 9
Thursday 16-Jan-14 10
Friday 17-Jan-14 11
Monday 20-Jan-14 12
Tuesday 21-Jan-14 13
Wednesday 22-Jan-14 14
Thursday 23-Jan-14 15
Friday 24-Jan-14 16
Monday 27-Jan-14 17
Tuesday 28-Jan-14 18
Wednesday 29-Jan-14 19
Thursday 30-Jan-14 20
Friday 31-Jan-14 21

With table, DateTable with a column Date of type Date, the following query will do what you ask.
SELECT
DATENAME(dw, Date) AS WeekDay
,Date
,ROW_NUMBER() OVER (ORDER BY Date) AS Day
FROM DateTable
WHERE DATEPART(dw, Date) NOT IN (1, 7)
ORDER BY Date

Based on the Title and subject, I am guessing that you want to try and identify the working day number of each month.
example:
1-Jan-14 is Wednesday so its Working day number 1
6-Jan-14 is Monday so its working day number 4 as (4-Jan-14 and 5-Jan-14 are Weekends)
Also the result should be a derived column in a table that already has data.
If the above is true then this is what I suggest
Create a function to calculate the working days between two dates.
(I have taken the last day of each oath as my initial date but you could also do +1 in you decide to go with first day of month way. (Personal preference really))
Alter table and add calculated column that calls the function
Sample Query:
IF OBJECT_ID('test') > 0
BEGIN
DROP TABLE test
END;
GO
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[ufn_WordkindDayNumber]') AND type in (N'FN', N'IF', N'TF', N'FS', N'FT'))
DROP FUNCTION [dbo].ufn_WordkindDayNumber
GO
CREATE FUNCTION ufn_WordkindDayNumber(#Date DATETIME)
RETURNS INT
AS
BEGIN
DECLARE #LastDayofPreviousMonth DATETIME,
#Return int
SET #LastDayofPreviousMonth = CAST(YEAR(#Date) as VARCHAR(4))+RIGHT('00'+CAST(MONTH(#Date) as VARCHAR(2)),2)+'01'
SET #LastDayofPreviousMonth = DATEADD (day, -1, CAST(#LastDayofPreviousMonth AS DATE))
-- Logic addapted from http://stackoverflow.com/questions/252519/count-work-days-between-two-dates. Credit CMS
SELECT #Return =
CASE
WHEN DATENAME(dw, #Date) = 'Sunday' OR DATENAME(dw, #Date) = 'Saturday' THEN 0
ELSE
(DATEDIFF(dd, #LastDayofPreviousMonth, #Date))
-(DATEDIFF(wk, #LastDayofPreviousMonth, #Date) * 2)
-(CASE WHEN DATENAME(dw, #Date) IN ('Saturday', 'Sunday') THEN 1 ELSE 0 END)
END
-- Return the result of the function
RETURN #Return
END
GO
CREATE TABLE test ([date] DATE NULL);
INSERT INTO test
SELECT '27-Dec-13' UNION ALL
SELECT '28-Dec-13' UNION ALL
SELECT '29-Dec-13'
ALTER TABLE test
ADD WordkindDayNumber AS dbo.ufn_WordkindDayNumber(Date);
GO
INSERT INTO test
SELECT '30-Dec-13' UNION ALL
SELECT '31-Dec-13'
SELECT *
FROM test;
DROP TABLE test;
Validation Script:
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[ufn_WordkindDayNumber]') AND type in (N'FN', N'IF', N'TF', N'FS', N'FT'))
DROP FUNCTION [dbo].ufn_WordkindDayNumber
GO
CREATE FUNCTION ufn_WordkindDayNumber(#Date DATETIME)
RETURNS INT
AS
BEGIN
DECLARE #LastDayofPreviousMonth DATETIME,
#Return int
SET #LastDayofPreviousMonth = CAST(YEAR(#Date) as VARCHAR(4))+RIGHT('00'+CAST(MONTH(#Date) as VARCHAR(2)),2)+'01'
SET #LastDayofPreviousMonth = DATEADD (day, -1, CAST(#LastDayofPreviousMonth AS DATE))
-- Logic addapted from http://stackoverflow.com/questions/252519/count-work-days-between-two-dates. Credit CMS
SELECT #Return =
CASE
WHEN DATENAME(dw, #Date) = 'Sunday' OR DATENAME(dw, #Date) = 'Saturday' THEN 0
ELSE
(DATEDIFF(dd, #LastDayofPreviousMonth, #Date))
-(DATEDIFF(wk, #LastDayofPreviousMonth, #Date) * 2)
-(CASE WHEN DATENAME(dw, #Date) IN ('Saturday', 'Sunday') THEN 1 ELSE 0 END)
END
-- Return the result of the function
RETURN #Return
END
GO
;WITH cte_TestData(Date) AS
(SELECT '30-Dec-13' UNION ALL
SELECT '31-Dec-13' UNION ALL
SELECT '1-Jan-14' UNION ALL
SELECT '2-Jan-14' UNION ALL
SELECT '3-Jan-14' UNION ALL
SELECT '4-Jan-14' UNION ALL
SELECT '5-Jan-14' UNION ALL
SELECT '6-Jan-14' UNION ALL
SELECT '7-Jan-14' UNION ALL
SELECT '8-Jan-14' UNION ALL
SELECT '9-Jan-14' UNION ALL
SELECT '10-Jan-14' UNION ALL
SELECT '11-Jan-14' UNION ALL
SELECT '12-Jan-14' UNION ALL
SELECT '13-Jan-14' UNION ALL
SELECT '14-Jan-14' UNION ALL
SELECT '15-Jan-14' UNION ALL
SELECT '16-Jan-14' UNION ALL
SELECT '17-Jan-14' UNION ALL
SELECT '18-Jan-14' UNION ALL
SELECT '19-Jan-14' UNION ALL
SELECT '20-Jan-14' UNION ALL
SELECT '21-Jan-14' UNION ALL
SELECT '22-Jan-14' UNION ALL
SELECT '23-Jan-14' UNION ALL
SELECT '24-Jan-14' UNION ALL
SELECT '25-Jan-14' UNION ALL
SELECT '26-Jan-14' UNION ALL
SELECT '27-Jan-14' UNION ALL
SELECT '28-Jan-14' UNION ALL
SELECT '29-Jan-14' UNION ALL
SELECT '30-Jan-14' UNION ALL
SELECT '31-Jan-14' )
,cte_FirstDateofMonth as
(
SELECT Date,
CAST(YEAR(DATE) as VARCHAR(4))+RIGHT('00'+CAST(MONTH(DATE) as VARCHAR(2)),2)+'01' AS FDoM
FROM cte_TestData
)
,cte_LastDayofPreviousMonth as
(
SELECT Date,
DATEADD (day, -1, CAST(FDoM AS DATE)) as LDoPM
FROM cte_FirstDateofMonth
)
SELECT [Date],
DATENAME(dw, Date) AS DatofWeek,
CASE
WHEN DATENAME(dw, Date) = 'Sunday' OR DATENAME(dw, Date) = 'Saturday' THEN 0
ELSE
DATEDIFF(dd, LDoPM, Date)
- (DATEDIFF(wk, LDoPM, Date) * 2)
- (CASE
WHEN DATENAME(dw, Date) = 'Sunday' OR DATENAME(dw, Date) = 'Saturday' THEN 1
ELSE 0
END)
END AS WordkindDayNumber,
dbo.ufn_WordkindDayNumber(Date) as FN_WordkindDayNumber
FROM cte_LastDayofPreviousMonth;

I created this solution which I think is simple, because you don't need to create a table:
DECLARE #Begin DATETIME = '20160628'
DECLARE #End DATETIME = '20160802 23:59'
;WITH Cte AS
(
SELECT
#Begin AS 'Dia'
,DATEPART(WEEKDAY,#Begin) AS DiaSemana
UNION ALL
SELECT
CteADD.Dia
,DATEPART(WEEKDAY,CteADD.Dia) AS DiaSemana
FROM
Cte
CROSS APPLY (SELECT DATEADD(DD,1,Cte.Dia) AS Dia ) CteADD
WHERE
CteADD.Dia < #End
)
SELECT
DiaSemana
,COUNT(DiaSemana) AS 'QntDias'
FROM
Cte
GROUP BY
DiaSemana

Related

How to get date between 2 days name from a table

I have 2 day names as input (For Example: "Friday" and "Monday". I need to get need to get all dates from a table in between those Friday and Monday (Friday, Saturday, Sunday, Monday) . If it is "Tuesday" and "Thursday" i need to get (Tuesday, Wednesday and Thursday )
My table is
If days are friday and monday. My Output should be
I tried this
SELECT
EMPLID, DUR, DayName, TRC
FROM DayTable
WHERE
DayName BETWEEN 'FRIDAY' AND 'MONDAY'
ORDER BY DUR ASC
but not working, Help me to solve this. Thanks in Advance
Try this query:
DECLARE #From int,#To int
Create Table #Days(Id int, DayOfWeek Varchar(100))
Insert into #Days Values
(1,'Sunday'),
(2,'Monday'),
(3,'Tuesday'),
(4,'Wednesday'),
(5,'Thursday'),
(6,'Friday'),
(7,'Saturday')
Select #From = Id from #Days where DayOfWeek = 'Friday'
Select #To = Id from #Days where DayOfWeek = 'Monday'
Select T.EMPLID, T.DUR, T.DayName, T.TRC from DayTable T
Inner Join #Days D on T.DayName = D.DayOfWeek AND (D.Id <= #To Or D.Id >= #From)
Hope this helps!
Update
Here's the same solution in a table valued function:
create function dbo.DaysBetween (
#DayFrom nvarchar(16)
, #DayTo nvarchar(16)
) returns #results table ([DayName] nvarchar(16))
as
begin
declare #daynames table (id smallint not null, [dayname] nvarchar(16) not null)
insert #daynames(id, [dayname])
values (0, 'Monday'),(1, 'Tuesday'),(2, 'Wednesday'),(3, 'Thursday'),(4, 'Friday'),(5, 'Saturday'),(6, 'Sunday')
declare #dayFromInt smallint
, #dayToInt smallint
select #dayFromInt = id from #daynames where [dayname] = #DayFrom
if (#dayFromInt is null)
begin
--hacky trick from https://stackoverflow.com/a/4681815/361842
set #dayFromInt = cast(('Invalid Day From Name: ' + #DayFrom) as int)
return
end
select #dayToInt = id from #daynames where [dayname] = #DayTo
if (#dayToInt is null)
begin
--hacky trick from https://stackoverflow.com/a/4681815/361842
set #dayToInt = cast(('Invalid Day To Name: '+ #DayTo) as int)
return
end
insert #results ([dayname])
select [dayname]
from #daynames
where
(
(#dayFromInt <= #dayToInt) and (id between #dayFromInt and #dayToInt)
or
(#dayFromInt > #dayToInt) and (id >= #dayFromInt or id <= #dayToInt)
)
return
end
go
Here are some example scenarios:
select * from dbo.DaysBetween('Monday','Friday')
select * from dbo.DaysBetween('Friday','Monday')
select * from dbo.DaysBetween('Tuesday','Thursday')
select * from dbo.DaysBetween('Thursday','Tuesday')
select * from dbo.DaysBetween('Christmasday','Monday')
go --required to get this result after the above error
select * from dbo.DaysBetween('Monday','Holiday')
To use this in your query, you'd do:
SELECT EMPLID
, DUR
, DayName
, TRC
FROM DayTable
WHERE
[DayName] in
(
select [DayName]
from dbo.DaysBetween('Friday','Monday')
)
ORDER BY DUR ASC
You cannot use the between operator like that. Datename returns a string, and the between operator is tru for all daynames that lexigraphically falls between "Friday" and "Monday".
I would suggest using
DayName in ('FRIDAY','SATURDAY','SUNDAY', 'MONDAY' )
Or use
set datefirst 2
...
where datepart(weekday,DUR)>3
If you use the DATEPART function on DUR, you will get the integer representation for the weekday.
So updating your WHERE clause:
SELECT
EMPLID, DUR, DayName, TRC
FROM DayTable
WHERE
DATEPART(weekday, DUR) BETWEEN 2 AND 6
ORDER BY DUR ASC
Where datepart will give you the weekday integer: SUN -> 1, MON-> 2 ... SAT -> 7
https://learn.microsoft.com/pt-br/sql/t-sql/functions/datepart-transact-sql
If you know your sql server's setting start day of the week is Sunday, then you can try this query :
SELECT
EMPLID, DUR, DayName, TRC
FROM DayTable
WHERE
DATEPART(WEEKDAY, DUR) <= 2 or DATEPART(WEEKDAY, DUR) >= 6
ORDER BY DUR ASC
Where week index of Monday = 2 and Friday = 6

Get all dates between two dates in SQL Server

How to get all the dates between two dates?
I have a variable #MAXDATE which is storing the maximum date from the table. Now I want to get the all dates between #Maxdate and GETDATE() and want to store these dates in a cursor.
So far I have done as follows:
;with GetDates As
(
select DATEADD(day,1,#maxDate) as TheDate
UNION ALL
select DATEADD(day,1, TheDate) from GetDates
where TheDate < GETDATE()
)
This is working perfectly but when I am trying to store these values in a cursor
SET #DateCurSor = CURSOR FOR
SELECT TheDate
FROM GetDates
Compilation Error
Incorrect syntax near the keyword 'SET'.
How to solve this?
My first suggestion would be use your calendar table, if you don't have one, then create one. They are very useful. Your query is then as simple as:
DECLARE #MinDate DATE = '20140101',
#MaxDate DATE = '20140106';
SELECT Date
FROM dbo.Calendar
WHERE Date >= #MinDate
AND Date < #MaxDate;
If you don't want to, or can't create a calendar table you can still do this on the fly without a recursive CTE:
DECLARE #MinDate DATE = '20140101',
#MaxDate DATE = '20140106';
SELECT TOP (DATEDIFF(DAY, #MinDate, #MaxDate) + 1)
Date = DATEADD(DAY, ROW_NUMBER() OVER(ORDER BY a.object_id) - 1, #MinDate)
FROM sys.all_objects a
CROSS JOIN sys.all_objects b;
For further reading on this see:
Generate a set or sequence without loops – part 1
Generate a set or sequence without loops – part 2
Generate a set or sequence without loops – part 3
With regard to then using this sequence of dates in a cursor, I would really recommend you find another way. There is usually a set based alternative that will perform much better.
So with your data:
date | it_cd | qty
24-04-14 | i-1 | 10
26-04-14 | i-1 | 20
To get the quantity on 28-04-2014 (which I gather is your requirement), you don't actually need any of the above, you can simply use:
SELECT TOP 1 date, it_cd, qty
FROM T
WHERE it_cd = 'i-1'
AND Date <= '20140428'
ORDER BY Date DESC;
If you don't want it for a particular item:
SELECT date, it_cd, qty
FROM ( SELECT date,
it_cd,
qty,
RowNumber = ROW_NUMBER() OVER(PARTITION BY ic_id
ORDER BY date DESC)
FROM T
WHERE Date <= '20140428'
) T
WHERE RowNumber = 1;
You can use this script to find dates between two dates. Reference taken from this Article:
DECLARE #StartDateTime DATETIME
DECLARE #EndDateTime DATETIME
SET #StartDateTime = '2015-01-01'
SET #EndDateTime = '2015-01-12';
WITH DateRange(DateData) AS
(
SELECT #StartDateTime as Date
UNION ALL
SELECT DATEADD(d,1,DateData)
FROM DateRange
WHERE DateData < #EndDateTime
)
SELECT DateData
FROM DateRange
OPTION (MAXRECURSION 0)
GO
Just saying...here is a more simple approach to this:
declare #sdate date = '2017-06-25'
, #edate date = '2017-07-24';
with dates_CTE (date) as (
select #sdate
Union ALL
select DATEADD(day, 1, date)
from dates_CTE
where date < #edate
)
select *
from dates_CTE;
Easily create a Table Value Function that will return a table with all dates.
Input dates as string
You can customize the date in the the format you like '01/01/2017' or '01-01-2017' in string formats (103,126 ...)
Try this
CREATE FUNCTION [dbo].[DateRange_To_Table] ( #minDate_Str NVARCHAR(30), #maxDate_Str NVARCHAR(30))
RETURNS #Result TABLE(DateString NVARCHAR(30) NOT NULL, DateNameString NVARCHAR(30) NOT NULL)
AS
begin
DECLARE #minDate DATETIME, #maxDate DATETIME
SET #minDate = CONVERT(Datetime, #minDate_Str,103)
SET #maxDate = CONVERT(Datetime, #maxDate_Str,103)
INSERT INTO #Result(DateString, DateNameString )
SELECT CONVERT(NVARCHAR(10),#minDate,103), CONVERT(NVARCHAR(30),DATENAME(dw,#minDate))
WHILE #maxDate > #minDate
BEGIN
SET #minDate = (SELECT DATEADD(dd,1,#minDate))
INSERT INTO #Result(DateString, DateNameString )
SELECT CONVERT(NVARCHAR(10),#minDate,103), CONVERT(NVARCHAR(30),DATENAME(dw,#minDate))
END
return
end
To execute the function do this:
SELECT * FROM dbo.DateRange_To_Table ('01/01/2017','31/01/2017')
The output will be
01/01/2017 Sunday
02/01/2017 Monday
03/01/2017 Tuesday
04/01/2017 Wednesday
05/01/2017 Thursday
06/01/2017 Friday
07/01/2017 Saturday
08/01/2017 Sunday
09/01/2017 Monday
10/01/2017 Tuesday
11/01/2017 Wednesday
12/01/2017 Thursday
13/01/2017 Friday
14/01/2017 Saturday
15/01/2017 Sunday
16/01/2017 Monday
17/01/2017 Tuesday
18/01/2017 Wednesday
19/01/2017 Thursday
20/01/2017 Friday
21/01/2017 Saturday
22/01/2017 Sunday
23/01/2017 Monday
24/01/2017 Tuesday
25/01/2017 Wednesday
26/01/2017 Thursday
27/01/2017 Friday
28/01/2017 Saturday
29/01/2017 Sunday
30/01/2017 Monday
31/01/2017 Tuesday
This can be considered as bit tricky way as in my situation, I can't use a CTE table, so decided to join with sys.all_objects and then created row numbers and added that to start date till it reached the end date.
See the code below where I generated all dates in Jul 2018. Replace hard coded dates with your own variables (tested in SQL Server 2016):
select top (datediff(dd, '2018-06-30', '2018-07-31')) ROW_NUMBER()
over(order by a.name) as SiNo,
Dateadd(dd, ROW_NUMBER() over(order by a.name) , '2018-06-30') as Dt from sys.all_objects a
You can try this:
SET LANGUAGE SPANISH
DECLARE #startDate DATE = GETDATE() -- Your start date
DECLARE #endDate DATE = DATEADD(MONTH, 16, GETDATE()) -- Your end date
DECLARE #years INT = YEAR(#endDate) - YEAR(#startDate)
CREATE TABLE #TMP_YEARS (
[year] INT
)
-- Get all posible years between the start and end date
WHILE #years >= 0
BEGIN
INSERT INTO #TMP_YEARS
([year])
SELECT YEAR(#startDate) + #years
SET #years = #years - 1
END
;WITH [days]([day]) AS -- Posible days at a month
(
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9 UNION ALL -- days lower than 10
SELECT 10 UNION ALL SELECT 11 UNION ALL SELECT 12 UNION ALL SELECT 13 UNION ALL SELECT 14 UNION ALL SELECT 15 UNION ALL SELECT 16 UNION ALL SELECT 17 UNION ALL SELECT 18 UNION ALL SELECT 19 UNION ALL -- days lower than 20
SELECT 20 UNION ALL SELECT 21 UNION ALL SELECT 22 UNION ALL SELECT 23 UNION ALL SELECT 24 UNION ALL SELECT 25 UNION ALL SELECT 26 UNION ALL SELECT 27 UNION ALL SELECT 28 UNION ALL SELECT 29 UNION ALL -- days lower than 30
SELECT 30 UNION ALL SELECT 31 -- days higher 30
),
[months]([month]) AS -- All months at a year
(
SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9 UNION ALL SELECT 10 UNION ALL SELECT 11 UNION ALL SELECT 12
)
SELECT CONVERT(VARCHAR, a.[year]) + '-' + REPLICATE('0', 2 - LEN(CONVERT(VARCHAR, n.[month]))) + CONVERT(VARCHAR, n.[month]) + '-' + REPLICATE('0', 2 - LEN(CONVERT(VARCHAR, d.[day]))) + CONVERT(VARCHAR, d.[day]) as [date]
FROM #TMP_YEARS a
CROSS JOIN [months] n -- Join all years with all months
INNER JOIN [days] d on DAY(EOMONTH(CONVERT(VARCHAR, a.[year]) + '-' + REPLICATE('0', 2 - LEN(CONVERT(VARCHAR, n.[month]))) + CONVERT(VARCHAR, n.[month]) + '-' + CONVERT(VARCHAR, DAY(EOMONTH(CAST(CONVERT(VARCHAR, a.[year]) + '-' + CONVERT(varchar, n.[month]) + '-15' AS DATE)))))) >= d.[day] AND -- The number of the day can't be higher than the last day of the current month and the current year
CONVERT(VARCHAR, a.[year]) + '-' + REPLICATE('0', 2 - LEN(CONVERT(VARCHAR, n.[month]))) + CONVERT(VARCHAR, n.[month]) + '-' + REPLICATE('0', 2 - LEN(CONVERT(VARCHAR, d.[day]))) + CONVERT(VARCHAR, d.[day]) <= ISNULL(#endDate, GETDATE()) AND -- The current date can't be higher than the end date
CONVERT(VARCHAR, a.[year]) + '-' + REPLICATE('0', 2 - LEN(CONVERT(VARCHAR, n.[month]))) + CONVERT(VARCHAR, n.[month]) + '-' + REPLICATE('0', 2 - LEN(CONVERT(VARCHAR, d.[day]))) + CONVERT(VARCHAR, d.[day]) >= ISNULL(#startDate, GETDATE()) -- The current date should be higher than the start date
ORDER BY a.[year] ASC, n.[month] ASC, d.[day] ASC
The output will be something like this, you can format the date as you like:
2019-01-24
2019-01-25
2019-01-26
2019-01-27
2019-01-28
2019-01-29
2019-01-30
2019-01-31
2019-02-01
2019-02-02
2019-02-03
2019-02-04
2019-02-05
2019-02-06
2019-02-07
2019-02-08
2019-02-09
...
create procedure [dbo].[p_display_dates](#startdate datetime,#enddate datetime)
as
begin
declare #mxdate datetime
declare #indate datetime
create table #daterange (dater datetime)
insert into #daterange values (#startdate)
set #mxdate = (select MAX(dater) from #daterange)
while #mxdate < #enddate
begin
set #indate = dateadd(day,1,#mxdate)
insert into #daterange values (#indate)
set #mxdate = (select MAX(dater) from #daterange)
end
select * from #daterange
end
I listed dates of 2 Weeks later. You can use variable #period OR function datediff(dd, #date_start, #date_end)
declare #period INT, #date_start datetime, #date_end datetime, #i int;
set #period = 14
set #date_start = convert(date,DATEADD(D, -#period, curent_timestamp))
set #date_end = convert(date,current_timestamp)
set #i = 1
create table #datesList(dts datetime)
insert into #datesList values (#date_start)
while #i <= #period
Begin
insert into #datesList values (dateadd(d,#i,#date_start))
set #i = #i + 1
end
select cast(dts as DATE) from #datesList
Drop Table #datesList
This is the method that I would use.
DECLARE
#DateFrom DATETIME = GETDATE(),
#DateTo DATETIME = DATEADD(HOUR, -1, GETDATE() + 2); -- Add 2 days and minus one hour
-- Dates spaced a day apart
WITH MyDates (MyDate)
AS (
SELECT #DateFrom
UNION ALL
SELECT DATEADD(DAY, 1, MyDate)
FROM MyDates
WHERE MyDate < #DateTo
)
SELECT
MyDates.MyDate
, CONVERT(DATE, MyDates.MyDate) AS [MyDate in DATE format]
FROM
MyDates;
Here is a similar example, but this time the dates are spaced one hour apart to further aid understanding of how the query works:
-- Alternative example with dates spaced an hour apart
WITH MyDates (MyDate)
AS (SELECT #DateFrom
UNION ALL
SELECT DATEADD(HOUR, 1, MyDate)
FROM MyDates
WHERE MyDate < #DateTo
)
SELECT
MyDates.MyDate
FROM
MyDates;
As you can see, the query is fast, accurate and versatile.
You can use SQL Server recursive CTE
DECLARE
#MinDate DATE = '2020-01-01',
#MaxDate DATE = '2020-02-01';
WITH Dates(day) AS
(
SELECT CAST(#MinDate as Date) as day
UNION ALL
SELECT CAST(DATEADD(day, 1, day) as Date) as day
FROM Dates
WHERE CAST(DATEADD(day, 1, day) as Date) < #MaxDate
)
SELECT* FROM dates;
declare #start_dt as date = '1/1/2021'; -- Date from which the calendar table will be created.
declare #end_dt as date = '1/1/2022'; -- Calendar table will be created up to this date (not including).
declare #dates as table (
date_id date primary key,
date_year smallint,
date_month tinyint,
date_day tinyint,
weekday_id tinyint,
weekday_nm varchar(10),
month_nm varchar(10),
day_of_year smallint,
quarter_id tinyint,
first_day_of_month date,
last_day_of_month date,
start_dts datetime,
end_dts datetime
)
while #start_dt < #end_dt
begin
insert into #dates(
date_id, date_year, date_month, date_day,
weekday_id, weekday_nm, month_nm, day_of_year, quarter_id,
first_day_of_month, last_day_of_month,
start_dts, end_dts
)
values(
#start_dt, year(#start_dt), month(#start_dt), day(#start_dt),
datepart(weekday, #start_dt), datename(weekday, #start_dt), datename(month, #start_dt), datepart(dayofyear, #start_dt), datepart(quarter, #start_dt),
dateadd(day,-(day(#start_dt)-1),#start_dt), dateadd(day,-(day(dateadd(month,1,#start_dt))),dateadd(month,1,#start_dt)),
cast(#start_dt as datetime), dateadd(second,-1,cast(dateadd(day, 1, #start_dt) as datetime))
)
set #start_dt = dateadd(day, 1, #start_dt)
end
-- sample of the data
select
top 50 *
--into master.dbo.DimDate
from #dates d
order by date_id
DECLARE #FirstDate DATE = '2018-01-01'
DECLARE #LastDate Date = '2018-12-31'
DECLARE #tbl TABLE(ID INT IDENTITY(1,1) PRIMARY KEY,CurrDate date)
INSERT #tbl VALUES( #FirstDate)
WHILE #FirstDate < #LastDate
BEGIN
SET #FirstDate = DATEADD( day,1, #FirstDate)
INSERT #tbl VALUES( #FirstDate)
END
INSERT #tbl VALUES( #LastDate)
SELECT * FROM #tbl

How to get all the weekend dates of the current year in SQL?

I tried but could not get the right solution. I want an SQL query that lists all the weekend dates of the current year.
I tried this SQL query:
WITH hier(num, lvl) AS (
SELECT 0, 1
UNION ALL
SELECT 100, 1
UNION ALL
SELECT num + 1, lvl + 1
FROM hier
WHERE lvl < 100
)
SELECT lvl [Week],
convert(date,DATEADD(dw, -DATEPART(dw, DATEADD(wk,DATEDIFF(wk,0,'12/31/'+convert(nvarchar,YEAR(getdate()))), 0)+6 ),
DATEADD(wk, DATEDIFF(wk,0,'12/31/'+convert(nvarchar,YEAR(getdate()))), 0)+6 ) - num * 7,101) [End Date]
FROM hier a
where num < 52
ORDER BY [End Date] asc
Its output is like this:
Week End date
52 2012-01-14
51 2012-01-21
50 2012-01-28
49 2012-02-04
I want the dates to start from the beginning – so, the above is missing one weekend, which is 2012-07-01. Also, I want the week numbers to show as 1, 2, 3... instead of 52, 51....
Check out this blog post.
Your question is explained in detail.
DECLARE #Year AS INT,
#FirstDateOfYear DATETIME,
#LastDateOfYear DATETIME
-- You can change #year to any year you desire
SELECT #year = 2010
SELECT #FirstDateOfYear = DATEADD(yyyy, #Year - 1900, 0)
SELECT #LastDateOfYear = DATEADD(yyyy, #Year - 1900 + 1, 0)
-- Creating Query to Prepare Year Data
;WITH cte AS (
SELECT 1 AS DayID,
#FirstDateOfYear AS FromDate,
DATENAME(dw, #FirstDateOfYear) AS Dayname
UNION ALL
SELECT cte.DayID + 1 AS DayID,
DATEADD(d, 1 ,cte.FromDate),
DATENAME(dw, DATEADD(d, 1 ,cte.FromDate)) AS Dayname
FROM cte
WHERE DATEADD(d,1,cte.FromDate) < #LastDateOfYear
)
SELECT FromDate AS Date, Dayname
FROM CTE
WHERE DayName IN ('Saturday','Sunday') -- For Weekend
/*
WHERE DayName LIKE 'Sunday'
WHERE DayName NOT IN ('Saturday','Sunday') -- For Weekday
WHERE DayName LIKE 'Monday' -- For Monday
WHERE DayName LIKE 'Sunday' -- For Sunday
*/
OPTION (MaxRecursion 370)
Will this help
DECLARE #startDate DATETIME, #endDate DATETIME
SELECT #startDate = '2012-01-01', #endDate = '2012-12-31'
;WITH Calender AS (
SELECT #startDate AS dt
UNION ALL
SELECT dt + 1 FROM Calender
WHERE dt + 1 <= #endDate
)
SELECT
dt
,NameMonth = DATENAME(Month, dt)
,NameDay = DATENAME (Weekday,dt)
,WeekofYr = DATEPART(WEEK, dt) FROM Calender
WHERE DATENAME (Weekday,dt) IN ('Sunday')
Option(MaxRecursion 0)
Result(Partial)
dt NameMonth NameDay WeekofYr
2012-01-01 00:00:00.000 January Sunday 1
2012-01-08 00:00:00.000 January Sunday 2
...............................................
...............................................
2012-12-30 00:00:00.000 December Sunday 53
you can try this
DECLARE #FirstDateOfYear DATETIME
SET #FirstDateOfYear = ’2010-01-01′
SELECT DISTINCT DATEADD(d, number, #FirstDateOfYear),
CASE DATEPART(dw, DATEADD(d, number, #FirstDateOfYear))
WHEN 7 THEN ‘Saturday’
WHEN 1 THEN ‘Sunday’
ELSE ‘Work Day’
END
FROM master..spt_values
WHERE number BETWEEN 0 AND 364
AND (DATEPART(dw, DATEADD(d, number, #FirstDateOfYear)) = 1 OR DATEPART(dw, DATEADD(d, number, #FirstDateOfYear)) = 7)
ORDER BY DATEADD(d, number, #FirstDateOfYear)
Try to find the first Saturday by doing this:
Start on 2012-01-01
If it's not a Saturday, add a day
Goto 2
Then, into a temporary table, add that date and the following date (Sunday).
After that, loop the following:
Add 7 and 8 days to the last Saturday you found (you get the following Saturday and Sunday)
Check whether they are still in 2012
If they are, store them in temp table and goto 1
There may be more elegant ways, but that's my quick & dirty solution. As you didn't post any code of what you've tried, I'll leave the implementation up to you.
this also works
declare #dat datetime, #add int
set #dat = '20120101'
set #add = datepart(w,#dat)
set #add = 5 - #add -- friday
set #dat = dateadd(d,#add,#dat)
while #dat <= '20121231'
begin
print #dat
set #dat = dateadd(d,7,#dat)
end
;with AllDaysOfYear (Day) as (
select DATEADD(year,DATEDIFF(year,0,CURRENT_TIMESTAMP),0) --Jan 1st
union all
select DATEADD(day,1,Day) from AllDaysOfYear
where DATEPART(year,DATEADD(day,1,Day)) = DATEPART(year,CURRENT_TIMESTAMP)
)
select
ROW_NUMBER() OVER (ORDER BY Day) as WeekNo,
Day
from
AllDaysOfYear
where
DATEPART(weekday,Day) = DATEPART(weekday,'20120714')
option (maxrecursion 0)
First, generate a set of all of the days in the current year (AllDaysInYear). Then, select those whose weekday is a saturday. The value I've used ('20120714') isn't terribly important - it just has to be any saturday, from any year. I'm just using it to avoid needing to have particular DATEFIRST or language settings.
This query shows how to get the first day of this year and the first day of the next year in the first part. The first day of the next year is calculated once so as not to keep getting and comparing the year parts.
;WITH cte(TheDate,NextYear) AS
(
SELECT CAST(CONVERT(CHAR(4),GETDATE(),112)+'0101' AS DATETIME),
CAST(YEAR(GETDATE())*10000+10101 AS CHAR(8))
UNION ALL
SELECT DateAdd(d,1,TheDate),NextYear
FROM cte
WHERE DateAdd(d,1,TheDate)<NextYear
)
SELECT Week = DatePart(wk,TheDate),
TheDate
FROM cte
WHERE DateName(dw,TheDate) in ('Saturday')
ORDER BY TheDate
OPTION (MAXRECURSION 366)
with t as
(
select 1 b
union all
select 1 b
union all
select 1 b
union all
select 1 b
union all
select 1 b
union all
select 1 b
union all
select 1 b
union all
select 1 b
)
select * from
(
select
current_timestamp
-datepart(dy,current_timestamp)
+row_number() over (order by t.b) d
from t, t t1, t t2
) tmp
where datepart(yyyy,d)=datepart(yyyy,current_timestamp)
and
DATENAME(dw,d)='sunday'
DECLARE #Year AS INT
SELECT #Year = 2020
;WITH weekends AS (
SELECT DATEFROMPARTS(#Year, 1, 1) AS dt
UNION ALL
SELECT DATEADD(DAY, 1, dt)
FROM weekends
WHERE dt < DATEFROMPARTS(#Year, 12, 31)
)
SELECT dt, DATENAME(MONTH, dt), DATENAME(DW, dt)
FROM weekends
WHERE DATEPART(DW, dt) IN (1, 7)
OPTION(MaxRecursion 366)

Get number of weekdays (Sundays, Mondays, Tuesdays) between two dates SQL

So, I'd like to, for a Start Date and End Date, determine how many particular days of the week occur between these two dates.
So how many mondays, tuesdays, etc
I know I can do this with a loop between the Start and End Date and check each day, but the difference could possibly be a great number of days. I'd prefer something that didn't require a loop. Any ideas? (Must be supported in SQL Server 2005+)
Given what I think you're trying to get, this should do it:
SET DATEFIRST 1
DECLARE
#start_date DATETIME,
#end_date DATETIME
SET #start_date = '2011-07-11'
SET #end_date = '2011-07-22'
;WITH Days_Of_The_Week AS (
SELECT 1 AS day_number, 'Monday' AS day_name UNION ALL
SELECT 2 AS day_number, 'Tuesday' AS day_name UNION ALL
SELECT 3 AS day_number, 'Wednesday' AS day_name UNION ALL
SELECT 4 AS day_number, 'Thursday' AS day_name UNION ALL
SELECT 5 AS day_number, 'Friday' AS day_name UNION ALL
SELECT 6 AS day_number, 'Saturday' AS day_name UNION ALL
SELECT 7 AS day_number, 'Sunday' AS day_name
)
SELECT
day_name,
1 + DATEDIFF(wk, #start_date, #end_date) -
CASE WHEN DATEPART(weekday, #start_date) > day_number THEN 1 ELSE 0 END -
CASE WHEN DATEPART(weekday, #end_date) < day_number THEN 1 ELSE 0 END
FROM
Days_Of_The_Week
I'm not sure what the OP is after, this will give a count per weeks day:
SET DATEFIRST 1
DECLARE #StartDate datetime
,#EndDate datetime
SELECT #StartDate='7/13/2011'
,#EndDate='7/28/2011'
;with AllDates AS
(
SELECT #StartDate AS DateOf, datename(weekday,#StartDate) AS WeekDayName, datepart(weekday,#StartDate) AS WeekDayNumber
UNION ALL
SELECT DateOf+1, datename(weekday,DateOf+1), datepart(weekday,DateOf+1)
FROM AllDates
WHERE DateOf<#EndDate
)
SELECT COUNT(*) CountOf,WeekDayName FROM AllDates GROUP BY WeekDayName,WeekDayNumber ORDER BY WeekDayNumber
OUTPUT:
CountOf WeekDayName
----------- ------------------------------
2 Monday
2 Tuesday
3 Wednesday
3 Thursday
2 Friday
2 Saturday
2 Sunday
(7 row(s) affected)
this will give a count of Monday to Friday days:
SET DATEFIRST 1
DECLARE #StartDate datetime
,#EndDate datetime
SELECT #StartDate='7/13/2011'
,#EndDate='7/28/2011'
;with AllDates AS
(
SELECT #StartDate AS DateOf, datepart(weekday,#StartDate) AS WeekDayNumber
UNION ALL
SELECT DateOf+1, datepart(weekday,DateOf+1)
FROM AllDates
WHERE DateOf<#EndDate
)
SELECT COUNT(*) AS WeekDayCount FROM AllDates WHERE WeekDayNumber<=5
OUTPUT:
WeekDayCount
------------
12
(1 row(s) affected)
If you have a holiday table, you can join it in and remove those as well. Here is a slightly different version that may preform better:
SET DATEFIRST 1
DECLARE #StartDate datetime
,#EndDate datetime
SELECT #StartDate='7/13/2011'
,#EndDate='7/28/2011'
;with AllDates AS
(
SELECT #StartDate AS DateOf, datepart(weekday,getdate()) AS WeekDayNumber
UNION ALL
SELECT DateOf+1, (WeekDayNumber+1) % 7
FROM AllDates
WHERE DateOf<#EndDate
)
SELECT COUNT(*) AS WeekDayCount FROM AllDates WHERE WeekDayNumber>0 AND WeekDayNumber<6
--I don't like using "BETWEEN", ">", ">=", "<", and "<=" are more explicit in defining end points
produces same output as original query.
This assume standard settings but cans be adapted
DECLARE #StartDate datetime, #EndDate datetime
SELECT #StartDate='20110601', #EndDate='20110630'
;WITH AllDates AS
(
SELECT #StartDate AS DateOf, datepart(weekday, #StartDate) AS WeekDayNumber
UNION ALL
SELECT DateOf+1, datepart(weekday, DateOf+1)
FROM AllDates
WHERE DateOf < #EndDate
)
SELECT SUM(CASE WHEN WeekDayNumber BETWEEN 2 AND 6 THEN 1 ELSE 0 END) AS WeekDayCount
FROM AllDates
OPTION (MAXRECURSION 0)
This should be valid for SQL Server, and should be internationlization safe (note: I do not have a server to test this against).
SELECT datediff(day, #start, #end) - datediff(week, #start, #end) * 2
- CASE WHEN datepart(weekday, #start)
IN (datepart(weekday, '1970-01-03'),
datepart(weekday, '1970-01-04'))
THEN 1
ELSE 0 END,
- CASE WHEN datepart(weekday, #end)
IN (datepart(weekday, '1970-01-03'),
datepart(weekday, '1970-01-04'))
THEN 1
ELSE 0 END
Give that a whirl.
Given the clarification, this should get the number of each of the days.
Uses no recursion, and should be completely international-safe. You will have to adjust start/end date parameters for inclusion/exclusion as necessary (The DB2 version I was using to check this excluded the start date, but included the end date, for example).
WITH dayOfWeek (name, dayNumber) as (VALUES(dayname(weekday, '1970-01-01'), daypart(weekday, '1970-01-01')),
(dayname(weekday, '1970-01-02'), daypart(weekday, '1970-01-02')),
(dayname(weekday, '1970-01-03'), daypart(weekday, '1970-01-03')),
(dayname(weekday, '1970-01-04'), daypart(weekday, '1970-01-04')),
(dayname(weekday, '1970-01-05'), daypart(weekday, '1970-01-05')),
(dayname(weekday, '1970-01-06'), daypart(weekday, '1970-01-06')),
(dayname(weekday, '1970-01-07'), daypart(weekday, '1970-01-07')))
SELECT name, dayNumber, datediff(weeks, #start, #end)
+ CASE WHEN datepart(weekday, #end) >= dayNumber THEN 1 ELSE 0 END
- CASE WHEN datepart(weekday, #start) >= dayNumber THEN 1 ELSE 0 END
FROM dayOfWeek
Does that help any?
you can use DATEDIFF and DATEPART functions + some basic math to get the desired result without looping.
I would have simply added as a comment to the marked answer, but do not have enough "reputation". Instead of hardcoding the day_number which is dependent on datefirst, you could set it by discovering the weekday for each day of the week:
;WITH Days_Of_The_Week AS (
SELECT DATEPART(dw, '2007-01-01') AS day_number, 'Monday' AS day_name UNION ALL -- 2007-01-01 is a known Monday
SELECT DATEPART(dw, '2007-01-02') AS day_number, 'Tuesday' AS day_name UNION ALL
SELECT DATEPART(dw, '2007-01-03') AS day_number, 'Wednesday' AS day_name UNION ALL
SELECT DATEPART(dw, '2007-01-04') AS day_number, 'Thursday' AS day_name UNION ALL
SELECT DATEPART(dw, '2007-01-05') AS day_number, 'Friday' AS day_name UNION ALL
SELECT DATEPART(dw, '2007-01-06') AS day_number, 'Saturday' AS day_name UNION ALL
SELECT DATEPART(dw, '2007-01-07') AS day_number, 'Sunday' AS day_name
)
#start_date date = '2017-08-11',
#end_date date = '2017-08-27',
#weekday int = 7,
#count int output
As
Begin
Declare #i int = 0
set #count = 0
while(#i <= (select Datediff(Day, #start_date, #end_date)))
begin
if(Dateadd(Day, #i, #start_date) > #end_date)
break
if(Datepart(weekday, Dateadd(Day, #i, #start_date)) = #weekday)
set #count += 1
set #i += 1
end
select #count

Calculating number of full months between two dates in SQL

I need to calculate the number of FULL month in SQL, i.e.
2009-04-16 to 2009-05-15 => 0 full month
2009-04-16 to 2009-05-16 => 1 full month
2009-04-16 to 2009-06-16 => 2 full months
I tried to use DATEDIFF, i.e.
SELECT DATEDIFF(MONTH, '2009-04-16', '2009-05-15')
but instead of giving me full months between the two date, it gives me the difference of the month part, i.e.
1
anyone know how to calculate the number of full months in SQL Server?
The original post had some bugs... so I re-wrote and packaged it as a UDF.
CREATE FUNCTION FullMonthsSeparation
(
#DateA DATETIME,
#DateB DATETIME
)
RETURNS INT
AS
BEGIN
DECLARE #Result INT
DECLARE #DateX DATETIME
DECLARE #DateY DATETIME
IF(#DateA < #DateB)
BEGIN
SET #DateX = #DateA
SET #DateY = #DateB
END
ELSE
BEGIN
SET #DateX = #DateB
SET #DateY = #DateA
END
SET #Result = (
SELECT
CASE
WHEN DATEPART(DAY, #DateX) > DATEPART(DAY, #DateY)
THEN DATEDIFF(MONTH, #DateX, #DateY) - 1
ELSE DATEDIFF(MONTH, #DateX, #DateY)
END
)
RETURN #Result
END
GO
SELECT dbo.FullMonthsSeparation('2009-04-16', '2009-05-15') as MonthSep -- =0
SELECT dbo.FullMonthsSeparation('2009-04-16', '2009-05-16') as MonthSep -- =1
SELECT dbo.FullMonthsSeparation('2009-04-16', '2009-06-16') as MonthSep -- =2
select case when DATEPART(D,End_dATE) >=DATEPART(D,sTAR_dATE)
THEN ( case when DATEPART(M,End_dATE) = DATEPART(M,sTAR_dATE) AND DATEPART(YYYY,End_dATE) = DATEPART(YYYY,sTAR_dATE)
THEN 0 ELSE DATEDIFF(M,sTAR_dATE,End_dATE)END )
ELSE DATEDIFF(M,sTAR_dATE,End_dATE)-1 END
What's your definition of a month? Technically a month can be 28,29,30 or 31 days depending on the month and leap years.
It seems you're considering a month to be 30 days since in your example you disregarded that May has 31 days, so why not just do the following?
SELECT DATEDIFF(DAY, '2009-04-16', '2009-05-15')/30
, DATEDIFF(DAY, '2009-04-16', '2009-05-16')/30
, DATEDIFF(DAY, '2009-04-16', '2009-06-16')/30
The dateadd function can be used to offset to the beginning of the month. If the endDate has a day part less than startDate, it will get pushed to the previous month, thus datediff will give the correct number of months.
DATEDIFF(MONTH, DATEADD(DAY,-DAY(startDate)+1,startDate),DATEADD(DAY,-DAY(startDate)+1,endDate))
This is for ORACLE only and not for SQL-Server:
months_between(to_date ('2009/05/15', 'yyyy/mm/dd'),
to_date ('2009/04/16', 'yyyy/mm/dd'))
And for full month:
round(months_between(to_date ('2009/05/15', 'yyyy/mm/dd'),
to_date ('2009/04/16', 'yyyy/mm/dd')))
Can be used in Oracle 8i and above.
I know this is an old question, but as long as the dates are >= 01-Jan-1753 I use:
DATEDIFF(MONTH, DATEADD(DAY,-DAY(#Start)+1,#Start),DATEADD(DAY,-DAY(#Start)+1,#End))
DATEDIFF() is designed to return the number boundaries crossed between the two dates for the span specified. To get it to do what you want, you need to make an additional adjustment to account for when the dates cross a boundary but don't complete the full span.
WITH
-- Count how many months must be added to #StartDate to exceed #DueDate
MONTHS_SINCE(n, [Month_hence], [IsFull], [RemainingDays] ) AS (
SELECT
1 as n,
DATEADD(Day, -1, DATEADD(Month, 1, #StartDate)) AS Month_hence
,CASE WHEN (DATEADD(Day, -1, DATEADD(Month, 1, #StartDate)) <= #LastDueDate)
THEN 1
ELSE 0
END AS [IsFull]
,DATEDIFF(day, #StartDate, #LastDueDate) as [RemainingDays]
UNION ALL
SELECT
n+1,
--DateAdd(Month, 1, Month_hence) as Month_hence -- No, causes propagation of short month discounted days
DATEADD(Day, -1, DATEADD(Month, n+1, #StartDate)) as Month_hence
,CASE WHEN (DATEADD(Day, -1, DATEADD(Month, n+1, #StartDate)) <= #LastDueDate)
THEN 1
ELSE 0
END AS [IsFull]
,DATEDIFF(day, DATEADD(Day, -1, DATEADD(Month, n, #StartDate)), #LastDueDate)
FROM MONTHS_SINCE
WHERE Month_hence<( #LastDueDate --WHERE Period= 1
)
), --SELECT * FROM MONTHS_SINCE
MONTH_TALLY (full_months_over_all_terms, months_over_all_terms, days_in_incomplete_month ) AS (
SELECT
COALESCE((SELECT MAX(n) FROM MONTHS_SINCE WHERE isFull = 1),1) as full_months_over_all_terms,
(SELECT MAX(n) FROM MONTHS_SINCE ) as months_over_all_terms,
COALESCE((SELECT [RemainingDays] FROM MONTHS_SINCE WHERE isFull = 0),0) as days_in_incomplete_month
) SELECT * FROM MONTH_TALLY;
Is not necesary to create the function only the #result part. For example:
Select Name,
(SELECT CASE WHEN
DATEPART(DAY, '2016-08-28') > DATEPART(DAY, '2016-09-29')
THEN DATEDIFF(MONTH, '2016-08-28', '2016-09-29') - 1
ELSE DATEDIFF(MONTH, '2016-08-28', '2016-09-29') END) as NumberOfMonths
FROM
tableExample;
This answer follows T-SQL format. I conceptualize this problem as one of a linear-time distance between two date points in datetime format, call them Time1 and Time2; Time1 should be aligned to the 'older in time' value you are dealing with (say a Birth date or a widget Creation date or a journey Start date) and Time2 should be aligned with the 'newer in time' value (say a snapshot date or a widget completion date or a journey checkpoint-reached date).
DECLARE #Time1 DATETIME
SET #Time1 = '12/14/2015'
DECLARE #Time2 DATETIME
SET #Time2 = '12/15/2016'
The solution leverages simple measurement, conversion and calculations of the serial intersections of multiple cycles of different lengths; here: Century,Decade,Year,Month,Day (Thanks Mayan Calendar for the concept!). A quick note of thanks: I thank other contributors to Stack Overflow for showing me some of the component functions in this process that I've stitched together. I've positively rated these in my time on this forum.
First, construct a horizon that is the linear set of the intersections of the Century,Decade,Year,Month cycles, incremental by month. Use the cross join Cartesian function for this. (Think of this as creating the cloth from which we will cut a length between two 'yyyy-mm' points in order to measure distance):
SELECT
Linear_YearMonths = (centuries.century + decades.decade + years.[year] + months.[Month]),
1 AS value
INTO #linear_months
FROM
(SELECT '18' [century] UNION ALL
SELECT '19' UNION ALL
SELECT '20') centuries
CROSS JOIN
(SELECT '0' [decade] UNION ALL
SELECT '1' UNION ALL
SELECT '2' UNION ALL
SELECT '3' UNION ALL
SELECT '4' UNION ALL
SELECT '5' UNION ALL
SELECT '6' UNION ALL
SELECT '7' UNION ALL
SELECT '8' UNION ALL
SELECT '9') decades
CROSS JOIN
(SELECT '1' [year] UNION ALL
SELECT '2' UNION ALL
SELECT '3' UNION ALL
SELECT '4' UNION ALL
SELECT '5' UNION ALL
SELECT '6' UNION ALL
SELECT '7' UNION ALL
SELECT '8' UNION ALL
SELECT '9' UNION ALL
SELECT '0') years
CROSS JOIN
(SELECT '-01' [month] UNION ALL
SELECT '-02' UNION ALL
SELECT '-03' UNION ALL
SELECT '-04' UNION ALL
SELECT '-05' UNION ALL
SELECT '-06' UNION ALL
SELECT '-07' UNION ALL
SELECT '-08' UNION ALL
SELECT '-09' UNION ALL
SELECT '-10' UNION ALL
SELECT '-11' UNION ALL
SELECT '-12') [months]
ORDER BY 1
Then, convert your Time1 and Time2 date points into the 'yyyy-mm' format (Think of these as the coordinate cut points on the whole cloth). Retain the original datetime versions of the points as well:
SELECT
Time1 = #Time1,
[YYYY-MM of Time1] = CASE
WHEN LEFT(MONTH(#Time1),1) <> '1' OR MONTH(#Time1) = '1'
THEN (CAST(YEAR(#Time1) AS VARCHAR) + '-' + '0' + CAST(MONTH(#Time1) AS VARCHAR))
ELSE (CAST(YEAR(#Time1) AS VARCHAR) + '-' + CAST(MONTH(#Time1) AS VARCHAR))
END,
Time2 = #Time2,
[YYYY-MM of Time2] = CASE
WHEN LEFT(MONTH(#Time2),1) <> '1' OR MONTH(#Time2) = '1'
THEN (CAST(YEAR(#Time2) AS VARCHAR) + '-' + '0' + CAST(MONTH(#Time2) AS VARCHAR))
ELSE (CAST(YEAR(#Time2) AS VARCHAR) + '-' + CAST(MONTH(#Time2) AS VARCHAR))
END
INTO #datepoints
Then, Select the ordinal distance of 'yyyy-mm' units, less one to convert to cardinal distance (i.e. cut a piece of cloth from the whole cloth at the identified cut points and get its raw measurement):
SELECT
d.*,
Months_Between = (SELECT (SUM(l.value) - 1) FROM #linear_months l
WHERE l.[Linear_YearMonths] BETWEEN d.[YYYY-MM of Time1] AND d.[YYYY-MM of Time2])
FROM #datepoints d
Raw Output:
I call this a 'raw distance' because the month component of the 'yyyy-mm' cardinal distance may be one too many; the day cycle components within the month need to be compared to see if this last month value should count. In this example specifically, the raw output distance is '12'. But this wrong as 12/14 is before 12/15, so therefore only 11 full months have lapsed--its just one day shy of lapsing through the 12th month. We therefore have to bring in the intra-month day cycle to get to a final answer. Insert a 'month,day' position comparison between the to determine if the latest date point month counts nominally, or not:
SELECT
d.*,
Months_Between = (SELECT (SUM(l.value) - 1) FROM AZ_VBP.[MY].[edg_Linear_YearMonths] l
WHERE l.[Linear_YearMonths] BETWEEN d.[YYYY-MM of Time1] AND d.[YYYY-MM of Time2])
+ (CASE WHEN DAY(Time1) < DAY(Time2)
THEN -1
ELSE 0
END)
FROM #datepoints d
Final Output:
The correct answer of '11' is now our output. And so, I hope this helps. Thanks!
select CAST(DATEDIFF(MONTH, StartDate, EndDate) AS float) -
(DATEPART(dd,StartDate) - 1.0) / DATEDIFF(DAY, StartDate, DATEADD(MONTH, 1, StartDate)) +
(DATEPART(dd,EndDate)*1.0 ) / DATEDIFF(DAY, EndDate, DATEADD(MONTH, 1, EndDate))
I realize this is an old post, but I created this interesting solution that I think is easy to implement using a CASE statement.
Estimate the difference using DATEDIFF, and then test the months before and after using DATEADD to find the best date. This assumes Jan 31 to Feb 28 is 1 month (because it is).
DECLARE #First date = '2015-08-31'
DECLARE #Last date = '2016-02-28'
SELECT
#First as [First],
#Last as [Last],
DateDiff(Month, #First, #Last) as [DateDiff Thinks],
CASE
WHEN DATEADD(Month, DATEDIFF(Month, #First, #Last) +1, #First) <= #Last Then DATEDIFF(Month, #First, #Last) +1
WHEN DATEADD(Month, DATEDIFF(Month, #First, #Last) , #First) <= #Last Then DATEDIFF(Month, #First, #Last)
WHEN DATEADD(Month, DATEDIFF(Month, #First, #Last) -1, #First) <= #Last Then DATEDIFF(Month, #First, #Last) -1
END as [Actual Months Apart]
SIMPLE AND EASY WAY, Just Copy and Paste this FULL code to MS SQL and Execute :
declare #StartDate date='2019-01-31'
declare #EndDate date='2019-02-28'
SELECT
DATEDIFF(MONTH, #StartDate, #EndDate)+
(
case
when format(#StartDate,'yyyy-MM') != format(#EndDate,'yyyy-MM') AND DATEPART(DAY,#StartDate) > DATEPART(DAY,#EndDate) AND DATEPART(DAY,#EndDate) = DATEPART(DAY,EOMONTH(#EndDate)) then 0
when format(#StartDate,'yyyy-MM') != format(#EndDate,'yyyy-MM') AND DATEPART(DAY,#StartDate) > DATEPART(DAY,#EndDate) then -1
else 0
end
)
as NumberOfMonths
All you need to do is deduct the additional month if the end date has not yet passed the day of the month in the start date.
DECLARE #StartDate AS DATE = '2019-07-17'
DECLARE #EndDate AS DATE = '2019-09-15'
DECLARE #MonthDiff AS INT = DATEDIFF(MONTH,#StartDate,#EndDate)
SELECT #MonthDiff -
CASE
WHEN FORMAT(#StartDate,'dd') > FORMAT(#EndDate,'dd') THEN 1
ELSE 0
END
You can create this function to calculate absolute difference between two dates.
As I found using DATEDIFF inbuilt system function we will get the difference only in months, days and years. For example : Let say there are two dates 18-Jan-2018 and 15-Jan-2019. So the difference between those dates will be given by DATEDIFF in month as 12 months where as it is actually 11 Months 28 Days. So using the function given below, we can find absolute difference between two dates.
CREATE FUNCTION GetDurationInMonthAndDays(#First_Date DateTime,#Second_Date DateTime)
RETURNS VARCHAR(500)
AS
BEGIN
DECLARE #RESULT VARCHAR(500)=''
DECLARE #MONTHS TABLE(MONTH_ID INT,MONTH_NAME VARCHAR(100),MONTH_DAYS INT)
INSERT INTO #MONTHS
SELECT 1,'Jan',31
union SELECT 2,'Feb',28
union SELECT 3,'Mar',31
union SELECT 4,'Apr',30
union SELECT 5,'May',31
union SELECT 6,'Jun',30
union SELECT 7,'Jul',31
union SELECT 8,'Aug',31
union SELECT 9,'Sep',30
union SELECT 10,'Oct',31
union SELECT 11,'Nov',30
union SELECT 12,'Jan',31
IF(#Second_Date>#First_Date)
BEGIN
declare #month int=0
declare #days int=0
declare #first_year int
declare #second_year int
SELECT #first_year=Year(#First_Date)
SELECT #second_year=Year(#Second_Date)+1
declare #first_month int
declare #second_month int
SELECT #first_month=Month(#First_Date)
SELECT #second_month=Month(#Second_Date)
if(#first_month=2)
begin
IF((#first_year%100<>0) AND (#first_year%4=0) OR (#first_year%400=0))
BEGIN
SELECT #days=29-day(#First_Date)
END
else
begin
SELECT #days=28-day(#First_Date)
end
end
else
begin
SELECT #days=(SELECT MONTH_DAYS FROM #MONTHS WHERE MONTH_ID=#first_month)-day(#First_Date)
end
SELECT #first_month=#first_month+1
WHILE #first_year<#second_year
BEGIN
if(#first_month=13)
begin
set #first_month=1
end
WHILE #first_month<13
BEGIN
if(#first_year=Year(#Second_Date))
begin
if(#first_month=#second_month)
begin
SELECT #days=#days+DAY(#Second_Date)
break;
end
else
begin
SELECT #month=#month+1
end
end
ELSE
BEGIN
SELECT #month=#month+1
END
SET #first_month=#first_month+1
END
SET #first_year = #first_year + 1
END
select #month=#month+(#days/30)
select #days=#days%30
if(#days>0)
begin
SELECT #RESULT=CAST(#month AS VARCHAR)+' Month '+CAST(#days AS VARCHAR)+' Days '
end
else
begin
SELECT #RESULT=CAST(#month AS VARCHAR)+' Month '
end
END
ELSE
BEGIN
SELECT #RESULT='ERROR'
END
RETURN #RESULT
END
SELECT dateadd(dd,number,DATEADD(yy, DATEDIFF(yy,0,getdate()), 0)) AS gun FROM master..spt_values
WHERE type = 'p'
AND year(dateadd(dd,number,DATEADD(yy, DATEDIFF(yy,0,getdate()), 0)))=year(DATEADD(yy, DATEDIFF(yy,0,getdate()), 0))
CREATE FUNCTION ufFullMonthDif (#dStart DATE, #dEnd DATE)
RETURNS INT
AS
BEGIN
DECLARE #dif INT,
#dEnd2 DATE
SET #dif = DATEDIFF(MONTH, #dStart, #dEnd)
SET #dEnd2 = DATEADD (MONTH, #dif, #dStart)
IF #dEnd2 > #dEnd
SET #dif = #dif - 1
RETURN #dif
END
GO
SELECT dbo.ufFullMonthDif ('2009-04-30', '2009-05-01')
SELECT dbo.ufFullMonthDif ('2009-04-30', '2009-05-29')
SELECT dbo.ufFullMonthDif ('2009-04-30', '2009-05-30')
SELECT dbo.ufFullMonthDif ('2009-04-16', '2009-05-15')
SELECT dbo.ufFullMonthDif ('2009-04-16', '2009-05-16')
SELECT dbo.ufFullMonthDif ('2009-04-16', '2009-06-16')
SELECT dbo.ufFullMonthDif ('2019-01-31', '2019-02-28')
Making Some changes to the Above function worked for me.
CREATE FUNCTION [dbo].[FullMonthsSeparation]
(
#DateA DATETIME,
#DateB DATETIME
)
RETURNS INT
AS
BEGIN
DECLARE #Result INT
DECLARE #DateX DATETIME
DECLARE #DateY DATETIME
IF(#DateA < #DateB)
BEGIN
SET #DateX = #DateA
SET #DateY = #DateB
END
ELSE
BEGIN
SET #DateX = #DateB
SET #DateY = #DateA
END
SET #Result = (
SELECT
CASE
WHEN DATEPART(DAY, #DateX) > DATEPART(DAY, #DateY)
THEN DATEDIFF(MONTH, #DateX, #DateY) - iif(EOMONTH(#DateY) = #DateY, 0, 1)
ELSE DATEDIFF(MONTH, #DateX, #DateY)
END
)
RETURN #Result
END
Declare #FromDate datetime, #ToDate datetime,
#TotalMonth int ='2021-10-01', #TotalDay='2021-12-31' int,
#Month int = 0
WHILE #ToDate > DATEADD(MONTH,#Month,#FromDate)
BEGIN
SET #Month = #Month +1
END
SET #TotalMonth = #Month -1
SET #TotalDay = DATEDIFF(DAY, DATEADD(MONTH,#TotalMonth, #FromDate),#ToDate) +1
IF(#TotalDay = DAY(EOMONTH(#ToDate)))
BEGIN
SET #TotalMonth = #TotalMonth +1
SET #TotalDay =0
END
Result #TotalMonth = 3, #TotalDay=0
if you are using PostGres only --
SELECT (DATE_PART('year', '2012-01-01'::date) - DATE_PART('year', '2011-10-02'::date)) * 12 +
(DATE_PART('month', '2012-01-01'::date) - DATE_PART('month', '2011-10-02'::date));
There are a lot of answers here that did not satisfy all the corner cases so I set about to fix them. This handles:
01/05/2021 - 02/04/2021 = 0 months
01/31/2021 - 02/28/2021 = 1 months
09/01/2021 - 10/31/2021 = 2 months
I think this generally handles all the cases needed.
declare #dateX date = '01/1/2022'
declare #datey date = '02/28/2022'
-- select datediff(month, #dateX, #datey) --Here for comparison
SELECT
CASE
WHEN DATEPART(DAY, #DateX) = 1 and DATEPART(DAY, #DateY) = DATEPART(DAY, eomonth(#DateY))
THEN DATEDIFF(MONTH, #DateX, #DateY) + 1
WHEN DATEPART(DAY, #DateX) > DATEPART(DAY, #DateY) and DATEPART(DAY, #DateY) != DATEPART(DAY, eomonth(#DateY))
THEN DATEDIFF(MONTH, #DateX, #DateY) - 1
ELSE DATEDIFF(MONTH, #DateX, #DateY)
END
I believe it is important to note that the question specifically asks for "full months between" AND that in the examples given each date is treated as "the START point of that date". This latter item is important because some comments state that year-01-31 to year-02-28 is a result of zero. This is correct. 1 complete day in January, plus 27 complete days in February (02-28 is the start of that day, so incomplete) is zero "full" months.
With that in mind I believe the following would meet the requirements IF StartDate is <= EndDate
(DATEPART(YEAR, EndDate) - DATEPART(YEAR, StartDate)) * 12
+ (DATEPART(MONTH, EndDate) - DATEPART(MONTH, StartDate))
- CASE WHEN DATEPART(DAY,EndDate) < DATEPART(DAY,StartDate) THEN 1 ELSE 0 END
To accommodate the possibility that the dates may be in any order then:
, CASE WHEN StartDate <= EndDate THEN
(DATEPART(YEAR, EndDate) - DATEPART(YEAR, StartDate)) * 12
+ (DATEPART(MONTH, EndDate) - DATEPART(MONTH, StartDate))
- CASE WHEN DATEPART(DAY,EndDate) < DATEPART(DAY,StartDate) THEN 1 ELSE 0 END
ELSE
(DATEPART(YEAR, StartDate) - DATEPART(YEAR, EndDate)) * 12
+ (DATEPART(MONTH, StartDate) - DATEPART(MONTH, EndDate))
- CASE WHEN DATEPART(DAY,StartDate) < DATEPART(DAY,EndDate) THEN 1 ELSE 0 END
END AS FullMnthsBtwn
For this sample:
select
StartDate, EndDate
into mytable
from (
values
(cast(getdate() as date),cast(getdate() as date)) -- both same date
-- original
,('2009-04-16','2009-05-15') -- > 0 full month
,('2009-04-16','2009-05-16') -- > 1 full month
,('2009-04-16','2009-06-16') -- > 2 full months
-- '1/31/2018' and endDate of '3/1/2018', I get a 0 – Eugene
, ('2018-01-31','2018-03-01')
-- some extras mentioned in comments, both of these should return 0 (in my opinion)
,('2009-01-31','2009-02-28')
,('2012-12-31','2013-02-28')
,('2022-05-15','2022-04-16') -- > 0 full month
,('2022-05-16','2022-04-16') -- > 1 full month
,('2021-06-16','2022-04-16') -- > 10 full months
) d (StartDate, EndDate)
query
select
StartDate
, EndDate
, CASE WHEN StartDate <= EndDate THEN
(DATEPART(YEAR, EndDate) - DATEPART(YEAR, StartDate)) * 12
+ (DATEPART(MONTH, EndDate) - DATEPART(MONTH, StartDate))
- CASE WHEN DATEPART(DAY,EndDate) < DATEPART(DAY,StartDate) THEN 1 ELSE 0 END
ELSE
(DATEPART(YEAR, StartDate) - DATEPART(YEAR, EndDate)) * 12
+ (DATEPART(MONTH, StartDate) - DATEPART(MONTH, EndDate))
- CASE WHEN DATEPART(DAY,StartDate) < DATEPART(DAY,EndDate) THEN 1 ELSE 0 END
END AS FullMnthsBtwn
from mytable
order by 1
result
+------------+------------+---------------+
| StartDate | EndDate | FullMnthsBtwn |
+------------+------------+---------------+
| 2009-01-31 | 2009-02-28 | 0 |
| 2009-04-16 | 2009-05-15 | 0 |
| 2009-04-16 | 2009-05-16 | 1 |
| 2009-04-16 | 2009-06-16 | 2 |
| 2012-12-31 | 2013-02-28 | 1 |
| 2018-01-31 | 2018-03-01 | 1 |
| 2021-06-16 | 2022-04-16 | 10 |
| 2022-05-15 | 2022-04-16 | 0 |
| 2022-05-16 | 2022-04-16 | 1 |
| 2022-07-09 | 2022-07-09 | 0 |
+------------+------------+---------------+
See db<>fiddle here (compares some other responses as well)
I got some ideas from the other answers, but none of them gave me exactly what I wanted.
The problem boils down to what I perceive a "month between" to be, which may be what others are also looking for also.
For example 25th February to 25th March would be one month to me, even though it is only 28 days. I would also consider 25th March to 25th April as one month at 31 days.
Also, I would consider 31st January to 2nd March as 1 month and 2 days even though it is 30 days between.
Also, fractions of a month are a bit meaningless as it depends on the length of a month and which month in the range do you choose to take a fraction of.
So, with that in mind, I came up with this function. It returns a decimal, the integer part is the number of months and the decimal part is the number of days, so a return value of 3.07 would mean 3 months and 7 days.
CREATE FUNCTION MonthsAndDaysBetween (#fromDt date, #toDt date)
RETURNS decimal(10,2)
AS
BEGIN
DECLARE #d1 date, #d2 date, #numM int, #numD int, #trc varchar(10);
IF(#fromDt < #toDt)
BEGIN
SET #d1 = #fromDt;
SET #d2 = #toDt;
END
ELSE
BEGIN
SET #d1 = #toDt;
SET #d2 = #fromDt;
END
IF DAY(#d1)>DAY(#d2)
SET #numM = year(#d2)*12+month(#d2)-year(#d1)*12-month(#d1)-1;
ELSE
SET #numM = year(#d2)*12+month(#d2)-year(#d1)*12-month(#d1);
IF YEAR(#d1) < YEAR(#d2) OR (YEAR(#d1) = YEAR(#d2) AND MONTH(#d1) < MONTH(#d2))
BEGIN
IF DAY(#d2) < DAY(#d1)
SET #numD = DAY(#d2) + DAY(EOMONTH(DATEADD(month,-1,#d2))) - DAY(#d1);
ELSE
SET #numD = DAY(#d2)-DAY(#d1);
END
ELSE
SET #numD = DAY(#d2)-DAY(#d1);
RETURN #numM + ABS(#numD) / 100.0;
END
In sql server, this formula works for going backward and forward in time.
DATEDIFF(month,#startdate, #enddate) + iif(#startdate <=#enddate,IIF(DAY(#startdate) > DAY(#enddate),-1,0),IIF(DAY(#startdate) < DAY(#enddate),+1, 0)))
SELECT 12 * (YEAR(end_date) - YEAR(start_date)) +
((MONTH(end_date) - MONTH(start_date))) +
SIGN(DAY(end_date) / DAY(start_date));
This works fine for me on SQL SERVER 2000.
Try:
trunc(Months_Between(date2, date1))
UPDATED
Right now, I just use
SELECT DATEDIFF(MONTH, '2019-01-31', '2019-02-28')
and SQL server returns the exact result (1).
I googled over internet.
And suggestion I found is to add +1 to the end.
Try do it like this:
Declare #Start DateTime
Declare #End DateTime
Set #Start = '11/1/07'
Set #End = '2/29/08'
Select DateDiff(Month, #Start, #End + 1)