how do I get this to display as it does there, in an email? I need to have the javascript and css work. Right now, neither do.

they won't

can it be done with an iframe?

Why don't you just use the style attribute instead of the CSS and set the date when it is created (which is what should happen anyway or else it will update every day for the person and won't show the reader when the newsletter was relevant).

And in the future when you make an array in javascript you can just set all of the elements with base zero straight away and this will work perfectly with the months (no need to add 1).

You may find this helpful regarding CSS support in HTML email.  Depending on the service/client, the support can range from basically the same as a modern browser, to almost none.  I had to deal with that for a work project last year and my short advice to you would be -- use as basic CSS as possible, use it in style attributes instead of relying on selectors.

Javascript in email is something you shouldn't even attempt.  It has been the source of many exploits in past and most modern clients will simply not execute it or severely limit what it can do.