You have a few options on your preferences to change your date format. Also, as an admin you can add various date formats for your users to choose from.
i've already made changes to the user options for the date format (to dd/mm/yy), however some features such as the calendar persist with the US format (eg, 6/12), which can be confusing and annoying.
if your code is by necessity hard-wired for the US date format, at the very least use a "mmm dd" format (eg, May 6) so that the world outside the US doesn't get confused.