DATEADD

Add one year to a given date and return the resulting date.

SELECT DATEADD(year, 1, ‘2017/08/25’) AS DateAdd;

Definition and Usage

The DATEADD() function adds a specified time or date interval to a given date and returns the resulting date.

DATEADD(interval, number, date)

Parameter	Description
interval	Required: Specify the time or date interval to add, using one of the following values: year, yyyy, yy: Year quarter, qq, q: Quarter month, mm, m: Month dayofyear, dy, y: Day of the year day, dd, d: Day week, ww, wk: Week weekday, dw, w: Weekday hour, hh: Hour minute, mi, n: Minute second, ss, s: Second millisecond, ms: Millisecond
number	Required: Specify the number of intervals to add to the date. Use positive values to calculate dates in the future and negative values for dates in the past.
date	Required: Specify the date that will be modified by adding the specified interval.

Works in:

SQL Server (beginning from 2008), Azure SQL Database, Azure SQL Data Warehouse, and Parallel Data Warehouse

Add two months to a given date and return the resulting date.

SELECT DATEADD(month, 2, ‘2017/08/25’) AS DateAdd;

Subtract two months from a specified date and return the resulting date.

SELECT DATEADD(month, –2, ‘2017/08/25’) AS DateAdd;

Add 18 years to the dates stored in the BirthDate column, then return the updated dates.

SELECT LastName, BirthDate, DATEADD(year, 18, BirthDate) AS DateAdd FROM Employees;