I just developed a clone of your flash clock to get rid of the "you have to install flash"-warnings of my browser. The clock has almost the same design like the original one.
The advantages of using a JavaScript clock instead of a flash clock is that almost every browser (AND mobile browsers!) supports javascript but not flash.
Please feel free to include this clock into the board3-source (it's GPLv2). I won't provide an full example how to integrate the clock into the portal because I don't know your coding style and where to push the js files. I think it's wrong to push any JavaScript-source into the style-directory, but do whatever you want. The phpBB file structure already is very random and the source code is full of surprising things
You can download the javascript source from here: https://gist.github.com/magcks/11153513
Example: http://m9x.de/projects/clock/
This one has the same size like the original one and should be easily includable into board3: http://m9x.de/projects/clock/simple.html
Have fun
Max
