Well yes. The argument you pass into the constructor of SimpleDateFormat
says the format you expect the date to be in.
"EEEE, MMMM/dd/yyyy"
would be valid for input like "Tuesday, February/26/2013". It's not even slightly valid for "2-26-2013". You do understand that you're parsing the text at the moment, not formatting it?
It looks like you want a format string of "M-dd-yyyy" or possibly "M-d-yyyy".
If you're trying to convert from one format to another, you need to first specify the format to parse, and then specify the format to format with:
SimpleDateFormat parser = new SimpleDateFormat("M-dd-yyyy");
SimpleDateFormat formatter = new SimpleDateFormat("EEEE, MMMM/dd/yyyy");
Date date = parser.parse(input);
String output = formatter.format(date);