Calendar Block

Hi,
I'm using the yui calendar block on a clients website.

By default, the latest added event is on the bottom of the list which shows when hovering the date. Which, in our case, doesn't make sense, as we don't want to highlight the ongoing events from the past on top, but the newest event.

As the calendar block doesn't have any settings like changing the order from ascending to descending, I already thought of an easy solution.
Simply reversing the list like so:
ul = $('.flyoutitemlist');
ul.children().each(function(i,li){ul.prepend(li)})

Unfortunately the calendar block can't be effected by any injected JS. To test it I tried things like: $('li').hide(); without an effect.

Why is that? And is there a workaround to use custom JS?

Kind regards and thanks in advance :)