SQL Server DAY() Function

The DAY() function in SQL Server extracts the day of the month from a date value. It's a simple but very useful function for working with dates and performing date-based filtering, calculations, or reporting.

DAY(): Definition and Usage

DAY() takes a date or datetime value and returns an integer representing the day of the month (a number between 1 and 31). This is helpful for various data manipulation and analysis tasks involving dates.

Syntax

DAY(date)
      

Parameter Values

Examples

Extracting the Day from a Date

This example extracts the day (25) from the date '2017/08/25'.

SELECT DAY('2017/08/25') AS DayOfMonth;
      

DayOfMonth
-----------
25
      

Extracting the Day from a DateTime

This example shows that DAY() works correctly with datetime values; it ignores the time portion and returns only the day of the month.

SELECT DAY('2017/08/13 09:08') AS DayOfMonth;
      

DayOfMonth
-----------
13