Get week day name from a given month day and year individually in SQL Server

Question

I'm attempting to get a day name like Friday, Saturday, Sunday, Monday, and so on from a given date. I realize there is an underlying capability that returns the day name for instance:

SELECT DATENAME(dw,'09/23/2013') as theDayName 

This SQL query returns:

'Monday'

This is all OK. Be that as it may, I might want to separately spend Month, Day and Year.

I'm utilizing the builtin DATEPART capability to recover month, day and year from a date so I can pass it to the DATENAME capability:

SELECT DATEPART(m, GETDATE()) as theMonth  -- returns 11
SELECT DATEPART(d, GETDATE()) as theDay   -- returns 20
SELECT DATEPART(yy, GETDATE()) as theYear   -- returns 2013

Now that I have Month, Day, Year values individually, I pass it to my DATENAME to get the Weekname of the date I want:

--my SQL query to return dayName
SELECT (DATENAME(dw, DATEPART(m, GETDATE())/DATEPART(d, myDateCol1)/ DATEPART(yy, getdate())))  as myNameOfDay, FirstName, LastName FROM myTable

This returns an incorrect Day Name. I tried to replace / with - so that in the DATENAME function my SQL query becomes:

SELECT DATENAME(dw,'09/23/2013') 
--becomes
SELECT DATENAME(dw,'09-23-2013') 

But it still returns incorrect dayName from my SQL query. Am I missing something here?