How can I calculate the number of work days between two dates in SQL Server?
Monday to Friday and it must be T-SQL.
24 Answers
For workdays, Monday to Friday, you can do it with a single SELECT, like this:
DECLARE @StartDate DATETIME
DECLARE @EndDate DATETIME
SET @StartDate = '2008/10/01'
SET @EndDate = '2008/10/31'
SELECT
(DATEDIFF(dd, @StartDate, @EndDate) + 1)
-(DATEDIFF(wk, @StartDate, @EndDate) * 2)
-(CASE WHEN DATENAME(dw, @StartDate) = 'Sunday' THEN 1 ELSE 0 END)
-(CASE WHEN DATENAME(dw, @EndDate) = 'Saturday' THEN 1 ELSE 0 END)
If you want to include holidays, you have to work it out a bit...
In Calculating Work Days you can find a good article about this subject, but as you can see it is not that advanced.
--Changing current database to the Master database allows function to be shared by everyone.
USE MASTER
GO
--If the function already exists, drop it.
IF EXISTS
(
SELECT *
FROM dbo.SYSOBJECTS
WHERE ID = OBJECT_ID(N'[dbo].[fn_WorkDays]')
AND XType IN (N'FN', N'IF', N'TF')
)
DROP FUNCTION [dbo].[fn_WorkDays]
GO
CREATE FUNCTION dbo.fn_WorkDays
--Presets
--Define the input parameters (OK if reversed by mistake).
(
@StartDate DATETIME,
@EndDate DATETIME = NULL --@EndDate replaced by @StartDate when DEFAULTed
)
--Define the output data type.
RETURNS INT
AS
--Calculate the RETURN of the function.
BEGIN
--Declare local variables
--Temporarily holds @EndDate during date reversal.
DECLARE @Swap DATETIME
--If the Start Date is null, return a NULL and exit.
IF @StartDate IS NULL
RETURN NULL
--If the End Date is null, populate with Start Date value so will have two dates (required by DATEDIFF below).
IF @EndDate IS NULL
SELECT @EndDate = @StartDate
--Strip the time element from both dates (just to be safe) by converting to whole days and back to a date.
--Usually faster than CONVERT.
--0 is a date (01/01/1900 00:00:00.000)
SELECT @StartDate = DATEADD(dd,DATEDIFF(dd,0,@StartDate), 0),
@EndDate = DATEADD(dd,DATEDIFF(dd,0,@EndDate) , 0)
--If the inputs are in the wrong order, reverse them.
IF @StartDate > @EndDate
SELECT @Swap = @EndDate,
@EndDate = @StartDate,
@StartDate = @Swap
--Calculate and return the number of workdays using the input parameters.
--This is the meat of the function.
--This is really just one formula with a couple of parts that are listed on separate lines for documentation purposes.
RETURN (
SELECT
--Start with total number of days including weekends
(DATEDIFF(dd,@StartDate, @EndDate)+1)
--Subtact 2 days for each full weekend
-(DATEDIFF(wk,@StartDate, @EndDate)*2)
--If StartDate is a Sunday, Subtract 1
-(CASE WHEN DATENAME(dw, @StartDate) = 'Sunday'
THEN 1
ELSE 0
END)
--If EndDate is a Saturday, Subtract 1
-(CASE WHEN DATENAME(dw, @EndDate) = 'Saturday'
THEN 1
ELSE 0
END)
)
END
GO
If you need to use a custom calendar, you might need to add some checks and some parameters. Hopefully it will provide a good starting point.
All Credit to Bogdan Maxim & Peter Mortensen. This is their post, I just added holidays to the function (This assumes you have a table "tblHolidays" with a datetime field "HolDate".
--Changing current database to the Master database allows function to be shared by everyone.
USE MASTER
GO
--If the function already exists, drop it.
IF EXISTS
(
SELECT *
FROM dbo.SYSOBJECTS
WHERE ID = OBJECT_ID(N'[dbo].[fn_WorkDays]')
AND XType IN (N'FN', N'IF', N'TF')
)
DROP FUNCTION [dbo].[fn_WorkDays]
GO
CREATE FUNCTION dbo.fn_WorkDays
--Presets
--Define the input parameters (OK if reversed by mistake).
(
@StartDate DATETIME,
@EndDate DATETIME = NULL --@EndDate replaced by @StartDate when DEFAULTed
)
--Define the output data type.
RETURNS INT
AS
--Calculate the RETURN of the function.
BEGIN
--Declare local variables
--Temporarily holds @EndDate during date reversal.
DECLARE @Swap DATETIME
--If the Start Date is null, return a NULL and exit.
IF @StartDate IS NULL
RETURN NULL
--If the End Date is null, populate with Start Date value so will have two dates (required by DATEDIFF below).
IF @EndDate IS NULL
SELECT @EndDate = @StartDate
--Strip the time element from both dates (just to be safe) by converting to whole days and back to a date.
--Usually faster than CONVERT.
--0 is a date (01/01/1900 00:00:00.000)
SELECT @StartDate = DATEADD(dd,DATEDIFF(dd,0,@StartDate), 0),
@EndDate = DATEADD(dd,DATEDIFF(dd,0,@EndDate) , 0)
--If the inputs are in the wrong order, reverse them.
IF @StartDate > @EndDate
SELECT @Swap = @EndDate,
@EndDate = @StartDate,
@StartDate = @Swap
--Calculate and return the number of workdays using the input parameters.
--This is the meat of the function.
--This is really just one formula with a couple of parts that are listed on separate lines for documentation purposes.
RETURN (
SELECT
--Start with total number of days including weekends
(DATEDIFF(dd,@StartDate, @EndDate)+1)
--Subtact 2 days for each full weekend
-(DATEDIFF(wk,@StartDate, @EndDate)*2)
--If StartDate is a Sunday, Subtract 1
-(CASE WHEN DATENAME(dw, @StartDate) = 'Sunday'
THEN 1
ELSE 0
END)
--If EndDate is a Saturday, Subtract 1
-(CASE WHEN DATENAME(dw, @EndDate) = 'Saturday'
THEN 1
ELSE 0
END)
--Subtract all holidays
-(Select Count(*) from [DB04\DB04].[Gateway].[dbo].[tblHolidays]
where [HolDate] between @StartDate and @EndDate )
)
END
GO
-- Test Script
/*
declare @EndDate datetime= dateadd(m,2,getdate())
print @EndDate
select [Master].[dbo].[fn_WorkDays] (getdate(), @EndDate)
*/
DECLARE @TotalDays INT,@WorkDays INT
DECLARE @ReducedDayswithEndDate INT
DECLARE @WeekPart INT
DECLARE @DatePart INT
SET @TotalDays= DATEDIFF(day, @StartDate, @EndDate) +1
SELECT @ReducedDayswithEndDate = CASE DATENAME(weekday, @EndDate)
WHEN 'Saturday' THEN 1
WHEN 'Sunday' THEN 2
ELSE 0 END
SET @TotalDays=@TotalDays-@ReducedDayswithEndDate
SET @WeekPart=@TotalDays/7;
SET @DatePart=@TotalDays%7;
SET @WorkDays=(@WeekPart*5)+@DatePart
RETURN @WorkDays
I know this is an old question but I needed a formula for workdays excluding the start date since I have several items and need the days to accumulate correctly.
None of the non-iterative answers worked for me.
I used a defintion like
Number of times midnight to monday, tuesday, wednesday, thursday and friday is passed
(others might count midnight to saturday instead of monday)
I ended up with this formula
SELECT DATEDIFF(day, @StartDate, @EndDate) /* all midnights passed */
- DATEDIFF(week, @StartDate, @EndDate) /* remove sunday midnights */
- DATEDIFF(week, DATEADD(day, 1, @StartDate), DATEADD(day, 1, @EndDate)) /* remove saturday midnights */
None of the functions above work for the same week or deal with holidays. I wrote this:
create FUNCTION [dbo].[ShiftHolidayToWorkday](@date date)
RETURNS date
AS
BEGIN
IF DATENAME( dw, @Date ) = 'Saturday'
SET @Date = DATEADD(day, - 1, @Date)
ELSE IF DATENAME( dw, @Date ) = 'Sunday'
SET @Date = DATEADD(day, 1, @Date)
RETURN @date
END
GO
create FUNCTION [dbo].[GetHoliday](@date date)
RETURNS varchar(50)
AS
BEGIN
declare @s varchar(50)
SELECT @s = CASE
WHEN dbo.ShiftHolidayToWorkday(CONVERT(varchar, [Year] ) + '-01-01') = @date THEN 'New Year'
WHEN dbo.ShiftHolidayToWorkday(CONVERT(varchar, [Year]+1) + '-01-01') = @date THEN 'New Year'
WHEN dbo.ShiftHolidayToWorkday(CONVERT(varchar, [Year] ) + '-07-04') = @date THEN 'Independence Day'
WHEN dbo.ShiftHolidayToWorkday(CONVERT(varchar, [Year] ) + '-12-25') = @date THEN 'Christmas Day'
--WHEN dbo.ShiftHolidayToWorkday(CONVERT(varchar, [Year]) + '-12-31') = @date THEN 'New Years Eve'
--WHEN dbo.ShiftHolidayToWorkday(CONVERT(varchar, [Year]) + '-11-11') = @date THEN 'Veteran''s Day'
WHEN [Month] = 1 AND [DayOfMonth] BETWEEN 15 AND 21 AND [DayName] = 'Monday' THEN 'Martin Luther King Day'
WHEN [Month] = 5 AND [DayOfMonth] >= 25 AND [DayName] = 'Monday' THEN 'Memorial Day'
WHEN [Month] = 9 AND [DayOfMonth] <= 7 AND [DayName] = 'Monday' THEN 'Labor Day'
WHEN [Month] = 11 AND [DayOfMonth] BETWEEN 22 AND 28 AND [DayName] = 'Thursday' THEN 'Thanksgiving Day'
WHEN [Month] = 11 AND [DayOfMonth] BETWEEN 23 AND 29 AND [DayName] = 'Friday' THEN 'Day After Thanksgiving'
ELSE NULL END
FROM (
SELECT
[Year] = YEAR(@date),
[Month] = MONTH(@date),
[DayOfMonth] = DAY(@date),
[DayName] = DATENAME(weekday,@date)
) c
RETURN @s
END
GO
create FUNCTION [dbo].GetHolidays(@year int)
RETURNS TABLE
AS
RETURN (
select dt, dbo.GetHoliday(dt) as Holiday
from (
select dateadd(day, number, convert(varchar,@year) + '-01-01') dt
from master..spt_values
where type='p'
) d
where year(dt) = @year and dbo.GetHoliday(dt) is not null
)
create proc UpdateHolidaysTable
as
if not exists(select TABLE_NAME from INFORMATION_SCHEMA.TABLES where TABLE_NAME = 'Holidays')
create table Holidays(dt date primary key clustered, Holiday varchar(50))
declare @year int
set @year = 1990
while @year < year(GetDate()) + 20
begin
insert into Holidays(dt, Holiday)
select a.dt, a.Holiday
from dbo.GetHolidays(@year) a
left join Holidays b on b.dt = a.dt
where b.dt is null
set @year = @year + 1
end
create FUNCTION [dbo].[GetWorkDays](@StartDate DATE = NULL, @EndDate DATE = NULL)
RETURNS INT
AS
BEGIN
IF @StartDate IS NULL OR @EndDate IS NULL
RETURN 0
IF @StartDate >= @EndDate
RETURN 0
DECLARE @Days int
SET @Days = 0
IF year(@StartDate) * 100 + datepart(week, @StartDate) = year(@EndDate) * 100 + datepart(week, @EndDate)
--same week
select @Days = (DATEDIFF(dd, @StartDate, @EndDate))
- (CASE WHEN DATENAME(dw, @StartDate) = 'Sunday' THEN 1 ELSE 0 END)
- (CASE WHEN DATENAME(dw, @EndDate) = 'Saturday' THEN 1 ELSE 0 END)
- (select count(*) from Holidays where dt between @StartDate and @EndDate)
ELSE
--diff weeks
select @Days = (DATEDIFF(dd, @StartDate, @EndDate) + 1)
- (DATEDIFF(wk, @StartDate, @EndDate) * 2)
- (CASE WHEN DATENAME(dw, @StartDate) = 'Sunday' THEN 1 ELSE 0 END)
- (CASE WHEN DATENAME(dw, @EndDate) = 'Saturday' THEN 1 ELSE 0 END)
- (select count(*) from Holidays where dt between @StartDate and @EndDate)
RETURN @Days
END
DECLARE @StartDate datetime,@EndDate datetime
select @StartDate='3/2/2010', @EndDate='3/7/2010'
DECLARE @TotalDays INT,@WorkDays INT
DECLARE @ReducedDayswithEndDate INT
DECLARE @WeekPart INT
DECLARE @DatePart INT
SET @TotalDays= DATEDIFF(day, @StartDate, @EndDate) +1
SELECT @ReducedDayswithEndDate = CASE DATENAME(weekday, @EndDate)
WHEN 'Saturday' THEN 1
WHEN 'Sunday' THEN 2
ELSE 0 END
SET @TotalDays=@TotalDays-@ReducedDayswithEndDate
SET @WeekPart=@TotalDays/7;
SET @DatePart=@TotalDays%7;
SET @WorkDays=(@WeekPart*5)+@DatePart
SELECT @WorkDays
As with DATEDIFF, I do not consider the end date to be part of the interval. The number of (for example) Sundays between @StartDate and @EndDate is the number of Sundays between an "initial" Monday and the @EndDate minus the number of Sundays between this "initial" Monday and the @StartDate. Knowing this, we can calculate the number of workdays as follows:
DECLARE @StartDate DATETIME
DECLARE @EndDate DATETIME
SET @StartDate = '2018/01/01'
SET @EndDate = '2019/01/01'
SELECT DATEDIFF(Day, @StartDate, @EndDate) -- Total Days
- (DATEDIFF(Day, 0, @EndDate)/7 - DATEDIFF(Day, 0, @StartDate)/7) -- Sundays
- (DATEDIFF(Day, -1, @EndDate)/7 - DATEDIFF(Day, -1, @StartDate)/7) -- Saturdays
Best regards!
I borrowed some ideas from others to create my solution. I use inline code to ignore weekends and U.S. federal holidays. In my environment, EndDate may be null, but it will never precede StartDate.
CREATE FUNCTION dbo.ufn_CalculateBusinessDays(
@StartDate DATE,
@EndDate DATE = NULL)
RETURNS INT
AS
BEGIN
DECLARE @TotalBusinessDays INT = 0;
DECLARE @TestDate DATE = @StartDate;
IF @EndDate IS NULL
RETURN NULL;
WHILE @TestDate < @EndDate
BEGIN
DECLARE @Month INT = DATEPART(MM, @TestDate);
DECLARE @Day INT = DATEPART(DD, @TestDate);
DECLARE @DayOfWeek INT = DATEPART(WEEKDAY, @TestDate) - 1; --Monday = 1, Tuesday = 2, etc.
DECLARE @DayOccurrence INT = (@Day - 1) / 7 + 1; --Nth day of month (3rd Monday, for example)
--Increment business day counter if not a weekend or holiday
SELECT @TotalBusinessDays += (
SELECT CASE
--Saturday OR Sunday
WHEN @DayOfWeek IN (6,7) THEN 0
--New Year's Day
WHEN @Month = 1 AND @Day = 1 THEN 0
--MLK Jr. Day
WHEN @Month = 1 AND @DayOfWeek = 1 AND @DayOccurrence = 3 THEN 0
--G. Washington's Birthday
WHEN @Month = 2 AND @DayOfWeek = 1 AND @DayOccurrence = 3 THEN 0
--Memorial Day
WHEN @Month = 5 AND @DayOfWeek = 1 AND @Day BETWEEN 25 AND 31 THEN 0
--Independence Day
WHEN @Month = 7 AND @Day = 4 THEN 0
--Labor Day
WHEN @Month = 9 AND @DayOfWeek = 1 AND @DayOccurrence = 1 THEN 0
--Columbus Day
WHEN @Month = 10 AND @DayOfWeek = 1 AND @DayOccurrence = 2 THEN 0
--Veterans Day
WHEN @Month = 11 AND @Day = 11 THEN 0
--Thanksgiving
WHEN @Month = 11 AND @DayOfWeek = 4 AND @DayOccurrence = 4 THEN 0
--Christmas
WHEN @Month = 12 AND @Day = 25 THEN 0
ELSE 1
END AS Result);
SET @TestDate = DATEADD(dd, 1, @TestDate);
END
RETURN @TotalBusinessDays;
END
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