Thanks to the script @ComplexPoint posted above, there is now a universal way to convert between date formats. I have built on his script, and provided a general purpose macro to do just this.
MACRO: Convert Date String from One Format to Another [Example]
Note that I have set the macro defaults to convert to the ISO format, which I think most people want. But you an easily change the default output format after you download install the macro. If you need any help with this, just post in the macro thread.