Datepart - Is the parameter that specifies the part of the date to return. Some of the supported types are year(yy, yyyy), ...

Datepart - Is the parameter that specifies the part of the date to return. Some of the supported types are year(yy, yyyy), month (mm, m)and dayofyear(dy, y). For complete supported list see Books Online. date - Is an expression that returns a datetime value, or a character string in a date format.