Get the Day Name from Date In SQL SERVER

In SQL
select datename (dw, '4/30/2012') as NameOfDay  --dw is refer as DATEPART
 the result is 'Monday'

 From this we can find the day of Date...

datepart

Is the parameter that specifies the part of the date to return. The following table lists dateparts and abbreviations recognized by Microsoft SQL Server 2005.

Datepart	Abbreviations
year	yy, yyyy
quarter	qq, q
month	mm, m
dayofyear	dy, y
day	dd, d
week	wk, ww
weekday	dw
hour	hh
minute	mi, n
second	ss, s
millisecond	ms

The weekday (dw) datepart returns the day of the week, such as Sunday, Monday, and so on.

 http://msdn.microsoft.com/en-us/library/ms174395%28v=sql.90%29.aspx