SQL Server DAY() Function

Return the day of the month for a date:

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

Definition and Usage

The DAY() function returns the day of the month (from 1 to 31) for a specified date.

DAY( date)

Parameter	Description
date	Required. The date to return the day of the month from

Works in:	SQL Server (starting with 2008), Azure SQL Database, Azure SQL Data Warehouse, Parallel Data Warehouse

Return the day of the month for a date:

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