DATEADD (Transact-SQL)

THIS TOPIC APPLIES TO: yesSQL Server (starting with 2008)yesAzure SQL DatabaseyesAzure SQL Data Warehouse yesParallel Data Warehouse

Returns a specified date with the specified number interval (signed integer) added to a specified datepart of that date.

For an overview of all Transact-SQL date and time data types and functions, see Date and Time Data Types and Functions (Transact-SQL).

Topic link icon Transact-SQL Syntax Conventions

Syntax

DATEADD (datepart , number , date )  

Arguments

datepart
Is the part of date to which an integernumber is added. The following table lists all valid datepart arguments. User-defined variable equivalents are not valid.

datepart Abbreviations
year yy, yyyy
quarter qq, q
month mm, m
dayofyear dy, y
day dd, d
week wk, ww
weekday dw, w
hour hh
minute mi, n
second ss, s
millisecond ms
microsecond mcs
nanosecond ns

number
Is an expression that can be resolved to an int that is added to a datepart of date. User-defined variables are valid.

If you specify a value with a decimal fraction, the fraction is truncated and not rounded.

date
Is an expression that can be resolved to a time, date, smalldatetime, datetime, datetime2, or datetimeoffset value. date can be an expression, column expression, user-defined variable, or string literal. If the expression is a string literal, it must resolve to a datetime. To avoid ambiguity, use four-digit years. For information about two-digit years, see Configure the two digit year cutoff Server Configuration Option.

Return Types

The return data type is the data type of the date argument, except for string literals.

The return data type for a string literal is datetime. An error will be raised if the string literal seconds scale is more than three positions (.nnn) or contains the time zone offset part.

Return Value

datepart Argument

dayofyear, day, and weekday return the same value.

Each datepart and its abbreviations return the same value.

If datepart is month and the date month has more days than the return month and the date day does not exist in the return month, the last day of the return month is returned. For example, September has 30 days; therefore, the two following statements return 2006-09-30 00:00:00.000:

SELECT DATEADD(month, 1, '2006-08-30');  
SELECT DATEADD(month, 1, '2006-08-31');

number Argument

The number argument cannot exceed the range of int. In the following statements, the argument for number exceeds the range of int by 1. The following error message is returned: "Msg 8115, Level 16, State 2, Line 1. Arithmetic overflow error converting expression to data type int."

SELECT DATEADD(year,2147483648, '2006-07-31');  
SELECT DATEADD(year,-2147483649, '2006-07-31');  

date Argument

The date argument cannot be incremented to a value outside the range of its data type. In the following statements, the number value that is added to the date value exceeds the range of the date data type. The following error message is returned: "Msg 517, Level 16, State 1, Line 1 Adding a value to a 'datetime' column caused overflow."

SELECT DATEADD(year,2147483647, '2006-07-31');  
SELECT DATEADD(year,-2147483647, '2006-07-31');  

Return Values for a smalldatetime date and a second or Fractional Seconds datepart

The seconds part of a smalldatetime value is always 00. If date is smalldatetime, the following apply:

  • If datepart is second and number is between -30 and +29, no addition is performed.
  • If datepart is second and number is less than-30 or more than +29, addition is performed beginning at one minute.
  • If datepart is millisecond and number is between -30001 and +29998, no addition is performed.
  • If datepart is millisecond and number is less than -30001 or more than +29998, addition is performed beginning at one minute.

Remarks

DATEADD can be used in the SELECT <list>, WHERE, HAVING, GROUP BY and ORDER BY clauses.

Fractional Seconds Precision

Addition for a datepart of microsecond or nanosecond for date data types smalldatetime, date, and datetime is not allowed.

Milliseconds have a scale of 3 (.123), microseconds have a scale of 6 (.123456), And nanoseconds have a scale of 9 (.123456789). The time, datetime2, and datetimeoffset data types have a maximum scale of 7 (.1234567). If datepart is nanosecond, number must be 100 before the fractional seconds of date increase. A number between 1 and 49 is rounded down to 0 and a number from 50 to 99 is rounded up to 100.

The following statements add a datepart of millisecond, microsecond, or nanosecond.

DECLARE @datetime2 datetime2 = '2007-01-01 13:10:10.1111111';  
SELECT '1 millisecond', DATEADD(millisecond,1,@datetime2)  
UNION ALL  
SELECT '2 milliseconds', DATEADD(millisecond,2,@datetime2)  
UNION ALL  
SELECT '1 microsecond', DATEADD(microsecond,1,@datetime2)  
UNION ALL  
SELECT '2 microseconds', DATEADD(microsecond,2,@datetime2)  
UNION ALL  
SELECT '49 nanoseconds', DATEADD(nanosecond,49,@datetime2)  
UNION ALL  
SELECT '50 nanoseconds', DATEADD(nanosecond,50,@datetime2)  
UNION ALL  
SELECT '150 nanoseconds', DATEADD(nanosecond,150,@datetime2);  

Here is the result set.

1 millisecond     2007-01-01 13:10:10.1121111  
2 milliseconds    2007-01-01 13:10:10.1131111  
1 microsecond     2007-01-01 13:10:10.1111121  
2 microseconds    2007-01-01 13:10:10.1111131  
49 nanoseconds    2007-01-01 13:10:10.1111111  
50 nanoseconds    2007-01-01 13:10:10.1111112  
150 nanoseconds   2007-01-01 13:10:10.1111113  

Time Zone Offset

Addition is not allowed for time zone offset.

Examples

A. Incrementing datepart by an interval of 1

Each of the following statements increments datepart by an interval of 1.

DECLARE @datetime2 datetime2 = '2007-01-01 13:10:10.1111111';  
SELECT 'year', DATEADD(year,1,@datetime2)  
UNION ALL  
SELECT 'quarter',DATEADD(quarter,1,@datetime2)  
UNION ALL  
SELECT 'month',DATEADD(month,1,@datetime2)  
UNION ALL  
SELECT 'dayofyear',DATEADD(dayofyear,1,@datetime2)  
UNION ALL  
SELECT 'day',DATEADD(day,1,@datetime2)  
UNION ALL  
SELECT 'week',DATEADD(week,1,@datetime2)  
UNION ALL  
SELECT 'weekday',DATEADD(weekday,1,@datetime2)  
UNION ALL  
SELECT 'hour',DATEADD(hour,1,@datetime2)  
UNION ALL  
SELECT 'minute',DATEADD(minute,1,@datetime2)  
UNION ALL  
SELECT 'second',DATEADD(second,1,@datetime2)  
UNION ALL  
SELECT 'millisecond',DATEADD(millisecond,1,@datetime2)  
UNION ALL  
SELECT 'microsecond',DATEADD(microsecond,1,@datetime2)  
UNION ALL  
SELECT 'nanosecond',DATEADD(nanosecond,1,@datetime2);  

Here is the result set.

Year         2008-01-01 13:10:10.1111111  
quarter      2007-04-01 13:10:10.1111111  
month        2007-02-01 13:10:10.1111111  
dayofyear    2007-01-02 13:10:10.1111111  
day          2007-01-02 13:10:10.1111111  
week         2007-01-08 13:10:10.1111111  
weekday      2007-01-02 13:10:10.1111111  
hour         2007-01-01 14:10:10.1111111  
minute       2007-01-01 13:11:10.1111111  
second       2007-01-01 13:10:11.1111111  
millisecond  2007-01-01 13:10:10.1121111  
microsecond  2007-01-01 13:10:10.1111121  
nanosecond   2007-01-01 13:10:10.1111111  

B. Incrementing more than one level of datepart in one statement

Each of the following statements increments datepart by a number large enough to also increment the next higher datepart of date.

DECLARE @datetime2 datetime2;  
SET @datetime2 = '2007-01-01 01:01:01.1111111';  
--Statement                                 Result     
-------------------------------------------------------------------   
SELECT DATEADD(quarter,4,@datetime2);     --2008-01-01 01:01:01.110  
SELECT DATEADD(month,13,@datetime2);      --2008-02-01 01:01:01.110  
SELECT DATEADD(dayofyear,365,@datetime2); --2008-01-01 01:01:01.110  
SELECT DATEADD(day,365,@datetime2);       --2008-01-01 01:01:01.110  
SELECT DATEADD(week,5,@datetime2);        --2007-02-05 01:01:01.110  
SELECT DATEADD(weekday,31,@datetime2);    --2007-02-01 01:01:01.110  
SELECT DATEADD(hour,23,@datetime2);       --2007-01-02 00:01:01.110  
SELECT DATEADD(minute,59,@datetime2);     --2007-01-01 02:00:01.110  
SELECT DATEADD(second,59,@datetime2);     --2007-01-01 01:02:00.110  
SELECT DATEADD(millisecond,1,@datetime2); --2007-01-01 01:01:01.110  

C. Using expressions as arguments for the number and date parameters

The following examples use different types of expressions as arguments for the number and date parameters. The examples use the AdventureWorks database.

Specifying a column as date

The following example adds 2 days to each value in the OrderDate column to derive a new column named PromisedShipDate.

SELECT SalesOrderID  
    ,OrderDate   
    ,DATEADD(day,2,OrderDate) AS PromisedShipDate  
FROM Sales.SalesOrderHeader;  

Here is a partial result set.

SalesOrderID OrderDate               PromisedShipDate  
------------ ----------------------- -----------------------  
43659        2005-07-01 00:00:00.000 2005-07-03 00:00:00.000  
43660        2005-07-01 00:00:00.000 2005-07-03 00:00:00.000  
43661        2005-07-01 00:00:00.000 2005-07-03 00:00:00.000  
...  
43702        2005-07-02 00:00:00.000 2005-07-04 00:00:00.000  
43703        2005-07-02 00:00:00.000 2005-07-04 00:00:00.000  
43704        2005-07-02 00:00:00.000 2005-07-04 00:00:00.000  
43705        2005-07-02 00:00:00.000 2005-07-04 00:00:00.000  
43706        2005-07-03 00:00:00.000 2005-07-05 00:00:00.000  
...  
43711        2005-07-04 00:00:00.000 2005-07-06 00:00:00.000  
43712        2005-07-04 00:00:00.000 2005-07-06 00:00:00.000  
...  
43740        2005-07-11 00:00:00.000 2005-07-13 00:00:00.000  
43741        2005-07-12 00:00:00.000 2005-07-14 00:00:00.000  

Specifying user-defined variables as number and date

The following example specifies user-defined variables as arguments for number and date.

DECLARE @days int = 365,   
        @datetime datetime = '2000-01-01 01:01:01.111'; /* 2000 was a leap year */;  
SELECT DATEADD(day, @days, @datetime);  

Here is the result set.

-----------------------  
2000-12-31 01:01:01.110  

(1 row(s) affected)  

Specifying scalar system function as date

The following example specifies SYSDATETIME for date.

SELECT DATEADD(month, 1, SYSDATETIME());  

Here is the result set.

---------------------------  
2013-02-06 14:29:59.6727944  

(1 row(s) affected)  

Specifying scalar subqueries and scalar functions as number and date

The following example uses scalar subqueries, MAX(ModifiedDate), as arguments for number and date. (SELECT TOP 1 BusinessEntityID FROM Person.Person) is an artificial argument for the number parameter to show how to select a number argument from a value list.

SELECT DATEADD(month,(SELECT TOP 1 BusinessEntityID FROM Person.Person),  
    (SELECT MAX(ModifiedDate) FROM Person.Person));  

Specifying numeric expressions and scalar system functions as number and date

The following example uses a numeric expression (-(10/2)), unary operators (-), an arithmetic operator (/), and scalar system functions (SYSDATETIME) as arguments for number and date.

SELECT DATEADD(month,-(10/2), SYSDATETIME());  

Specifying ranking functions as number

The following example uses a ranking function as arguments for number.

SELECT p.FirstName, p.LastName  
    ,DATEADD(day,ROW_NUMBER() OVER (ORDER BY  
        a.PostalCode),SYSDATETIME()) AS 'Row Number'  
FROM Sales.SalesPerson AS s   
    INNER JOIN Person.Person AS p   
        ON s.BusinessEntityID = p.BusinessEntityID  
    INNER JOIN Person.Address AS a   
        ON a.AddressID = p.BusinessEntityID  
WHERE TerritoryID IS NOT NULL   
    AND SalesYTD <> 0;  

Specifying an aggregate window function as number

The following example uses an aggregate window function as an argument for number.

SELECT SalesOrderID, ProductID, OrderQty  
    ,DATEADD(day,SUM(OrderQty)   
        OVER(PARTITION BY SalesOrderID),SYSDATETIME()) AS 'Total'  
FROM Sales.SalesOrderDetail   
WHERE SalesOrderID IN(43659,43664);  
GO  

See Also

CAST and CONVERT (Transact-SQL)