Jquery Validation plugin validate date like 20/August/2013

Jquery Validation plugin validate date like 20/August/2013

i know that Jquery Validation plugin supports custom validation like
$.validator.addMethod("customdatevalidat", function(value, element)
{
return _isvalid;
}
how can i validate a date format like "23/August/2013" ('dd/MM/yy')
i tried Custom date format with jQuery validation plugin but wouldn't
helped as its in dd/mm/yyyy not for ('dd/MM/yy') , then what is the regex
for this "23/August/2013" any one can help me?