DATEADD (Transact-SQL)

**APPLIES TO:** SQL Server (starting with 2008) Azure SQL Database Azure SQL Data Warehouse Parallel Data Warehouse

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This function adds a specified number value (as a signed integer) to a specified datepart of an input date value, and then returns that modified value.

See Date and Time Data Types and Functions (Transact-SQL) for an overview of all Transact\-SQL date and time data types and functions.

Transact-SQL Syntax Conventions

Syntax

DATEADD (datepart , number , date )  

Arguments

datepart
The part of date to which DATEADD adds an integer number. This table lists all valid datepart arguments.

[!NOTE] DATEADD does not accept user-defined variable equivalents for the datepart arguments.

number
An expression that can resolve to an int that DATEADD adds to a datepart of date. DATEADD accepts user-defined variable values for number. DATEADD will truncate a specified number value that has a decimal fraction. It will not round the number value in this situation.

date
An expression that can resolve to one of the following values:

• date
• datetime
• datetimeoffset
• datetime2
• smalldatetime
• time

For date, DATEADD will accept a column expression, expression, string literal, or user-defined variable. A string literal value must resolve to a datetime. Use four-digit years to avoid ambiguity issues. See Configure the two digit year cutoff Server Configuration Option for information about two-digit years.

Return types

The date argument data type becomes the DATEADD return value data type, except for string literal date values. For a string literal, DATEADD returns a datetime value. DATEADD will raise an error if the string literal seconds scale exceeds three decimal place positions (.nnn) or if the string literal 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 the following are true:

• datepart is month
• the date month has more days than the return month
• the date day does not exist in the return month

Then, DATEADD returns the last day of the return month. For example, September has 30 (thirty) days; therefore, these statements return 2006-09-30 00:00:00.000:

SELECT DATEADD(month, 1, '20060830');
SELECT DATEADD(month, 1, '20060831');

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. These statements both return the following error message: "Msg 8115, Level 16, State 2, Line 1. Arithmetic overflow error converting expression to data type int."

SELECT DATEADD(year,2147483648, '20060731');  
SELECT DATEADD(year,-2147483649, '20060731');  

date Argument

DATEADD will not accept a date argument incremented to a value outside the range of its data type. In the following statements, the number value added to the date value exceeds the range of the date data type. DATEADD returns the following error message: “Msg 517, Level 16, State 1, Line 1 Adding a value to a 'datetime' column caused overflow.”

SELECT DATEADD(year,2147483647, '20060731');  
SELECT DATEADD(year,-2147483647, '20060731');  

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

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

• For a datepart of second, and a number value between -30 and +29, DATEADD makes no changes.
  
• For a datepart of second, and a number value less than -30, or more than +29, DATEADD performs its addition beginning at one minute.
  
• For a datepart of millisecond and a number value between -30001 and +29998, DATEADD makes no changes.
  
• For a datepart of millisecond and a number value less than -30001, or more than +29998, DATEADD performs its addition beginning at one minute.

Remarks

Use DATEADD in the following clauses:

• GROUP BY
• HAVING
• ORDER BY
• SELECT <list>
• WHERE

Fractional seconds precision

DATEADD does not allow addition for a datepart of microsecond or nanosecond for date data types smalldatetime, date, and datetime.

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). For a datepart of nanosecond, number must be 100 before the fractional seconds of date increase. A number between 1 and 49 will round down to 0, and a number from 50 to 99 rounds up to 100.

These 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

DATEADD does not allow addition for time zone offset.

Examples

A. Incrementing datepart by an interval of 1

Each of these 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 these statements increments datepart by a number large enough to additionally 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 01:01:01.1111111  
SELECT DATEADD(month,13,@datetime2);      --2008-02-01 01:01:01.1111111  
SELECT DATEADD(dayofyear,365,@datetime2); --2008-01-01 01:01:01.1111111  
SELECT DATEADD(day,365,@datetime2);       --2008-01-01 01:01:01.1111111  
SELECT DATEADD(week,5,@datetime2);        --2007-02-05 01:01:01.1111111  
SELECT DATEADD(weekday,31,@datetime2);    --2007-02-01 01:01:01.1111111  
SELECT DATEADD(hour,23,@datetime2);       --2007-01-02 00:01:01.1111111  
SELECT DATEADD(minute,59,@datetime2);     --2007-01-01 02:00:01.1111111  
SELECT DATEADD(second,59,@datetime2);     --2007-01-01 01:02:00.1111111  
SELECT DATEADD(millisecond,1,@datetime2); --2007-01-01 01:01:01.1121111  

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

These 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

This example adds 2 (two) 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;  

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

This 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

This example specifies SYSDATETIME for date. The exact value returned depends on the day and time of statement execution:

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

This example uses scalar subqueries, MAX(ModifiedDate), as arguments for number and date. (SELECT TOP 1 BusinessEntityID FROM Person.Person) serves as 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

This 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

This example uses a ranking function as an argument 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

This 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)