Maybe I'm psychic and could tell that you've already tried them? Maybe I even know what the results of your attempts were so that they could help me debug the problem? Maybe I even know what you did wrong? Maybe you should learn how to ask questions that don't waste your time as well as everybody else's?
Here, I'm feeling generous. I'll do it all for you.
$date = "Mon, 05 Dec 2005 16:38:22";
echo date("j M, g.ia", strtotime($date));
Huh. Works for me. Assuming you do want the output in the same timezone as the input, and not UTC or server-local time (which would respectively be "5 Dec, 3.38pm" and "6 Dec, 4.38am").