Date format issues

I've checked the forum for information on formatting the date. The date format appearing on my admin, customer info, etc. is month/day/year; May/Wed/2011.
I changed the date format within the main english.php files in the language/english folder from DD/MM/YY to MM/DD/YY and now I get May/Wed/2011.
How do I get it to appear as May/25/2011?

thanks