Returns a new datetime value based on adding an interval to the specified date.
Is the parameter that specifies on which part of the date to return a new value. The following table lists the dateparts and abbreviations recognized by Microsoft SQL Server 2005.
Is the value used to increment datepart. If you specify a value that is not an integer, the fractional part of the value is discarded. For example, if you specify day for datepart and1.75 for number, date is incremented by 1.
If you specify only the last two digits of the year, values less than or equal to the last two digits of the value of the two digit year cutoff configuration option are in the same century as the cutoff year. Values greater than the last two digits of the value of this option are in the century that comes before the cutoff year. For example, if two-digit year cutoff is 2049 (default), 49 is interpreted as 2049 and 2050 is interpreted as 1950. To avoid ambiguity, use four-digit years.
When datepart is month, the number of days in the month affects the result. For example, August has 31 days and September has 30 days. Both of the following statements return
SELECT DATEADD(month, 1, '08/30/2006') SELECT DATEADD(month, 1, '08/31/2006')
In other words, adding one month to the end of August returns the last day of September.
The following example prints a listing of a time frame for orders in the
AdventureWorks database. This time frame represents the existing order date plus
USE AdventureWorks; GO SELECT DATEADD(day, 21, OrderDate)AS TimeFrame FROM Sales.SalesOrderHeader; GO