Does this sound grammatically off

Rapp   Mon Jul 20, 2009 1:21 pm GMT
Its really not worth arguing over, but that link is to a website at Perdue University that explains the MLA recommended style. Given that it recommends commas in that situation, and doesn't recommend dashes anywhere, I would think that commas are standard.

If you want to use dashes, knock yourself out. The meaning of the sentence is certainly still clear. But your writing will look pretty funky if you do that commonly.