Returns a character string that represents the specified datepart of the specified date
For an overview of all Transact-SQL date and time data types and functions, see Date and Time Functions (Transact-SQL). For information and examples that are common to date and time data types and functions, see Using Date and Time Data.
Each datepart and its abbreviations return the same value.
The return value depends on the language environment set by using SET LANGUAGE and by the default language of the login. The return value is dependant on SET DATEFORMAT if date is a string literal of some formats. SET DATEFORMAT does not affect the return value when the date is a column expression of a date or time data type.
For versions of SQL Server later than SQL Server 2000, when the date parameter has a date data type argument, the return value depends on the setting specified by using SET DATEFIRST.
If the data type of the date argument does not have the specified datepart, the default for that datepart will be returned.
For example, the default year-month-day for any date data type is 1900-01-01. The following statement has date part arguments for datepart, a time argument for date, and returns 1900, January, 1, 1, Monday.
SELECT DATENAME(year, '12:10:30.123') ,DATENAME(month, '12:10:30.123') ,DATENAME(day, '12:10:30.123') ,DATENAME(dayofyear, '12:10:30.123') ,DATENAME(weekday, '12:10:30.123');
The default hour-minute-second for the time data type is 00:00:00. The following statement has time part arguments for datepart, a date argument for date, and returns 0, 0, 0.
SELECT DATENAME(hour, '2007-06-01') ,DATENAME(minute, '2007-06-01') ,DATENAME(second, '2007-06-01');
DATENAME can be used in the select list, WHERE, HAVING, GROUP BY, and ORDER BY clauses. In SQL Server 2008 R2, DATENAME implicitly casts string literals as a datetime2 type. This means that DATEDIFF no longer supports the format YDM when the date is passed as a string. You must explicitly cast the string to a datetime or smalldatetime type to use the YDM format.
The following example returns the date parts for the specified date.
SELECT DATENAME(datepart,'2007-10-30 12:15:32.1234567 +05:10')
Here is the result set.
year, yyyy, yy
quarter, qq, q
month, mm, m
dayofyear, dy, y
day, dd, d
week, wk, ww
second, ss, s