Returns an integer that represents the day in the datepart of a specified date.
day(date_expression)
is an expression of type datetime, smalldatetime, date or a character string in a datetime format.
Returns the integer 02:
day("11/02/03") ---------- 02
day(date_expression) is equivalent to datepart(dd,date_expression).
ANSI SQL – Compliance level: Transact-SQL extension.
Any user can execute day.