SQL Server DATEADD() Function

The DATEADD() function is a function in SQL Server used to add or subtract a specified time interval from a date. It is commonly used in queries to calculate dates and can add time intervals such as years, months, days, hours, and minutes.

Syntax

DATEADD(datepart, number, date)

Parameters:

datepart: represents the time interval to be added and can be one of the following values:
- year: year
- quarter: quarter
- month: month
- dayofyear: day of the year
- day: day
- week: week
- weekday: weekday
- hour: hour
- minute: minute
- second: second
- millisecond: millisecond
number: represents the number of the time interval to be added
date: represents the date to which the time interval is to be added

Usage

The DATEADD() function is very useful for date calculations in queries, for example:

Calculate a date a certain number of days from another date
Calculate a date a certain number of months from another date
Calculate a date a certain number of years from another date
Calculate a date a certain number of hours from another date
Calculate a date a certain number of minutes from another date

Examples

Example 1: Calculate a date a certain number of days from another date

Suppose we want to calculate the date 7 days after March 11, 2023. We can use the following SQL statement:

SELECT DATEADD(day, 7, '2023-03-11') AS Result;

The result of the query is:

Result
2023-03-18

Example 2: Calculate a date a certain number of months from another date

Suppose we want to calculate the date 3 months after March 11, 2023. We can use the following SQL statement:

SELECT DATEADD(month, 3, '2023-03-11') AS Result;