The RSS Feed template shows "Posted on Tue May 05 07:21:45 EDT 2009 by Pete Muir". It's pretty obvious that it has been posted and the time down to the second really doesn't matter. Also, the day should be first because most people will have more than one news item in one month.

So it would be nicer and easier to read: "05 May 2009 07:21 EDT by Pete Muir