Glad you got it sorted. I keep mine as the default, but I have played with it a few times over the years. It just takes bit of tinkering to figure out how it all works with all the different formats (short, medium, long, full) and copying and pasting some of the fields between windows. And there's the separate options for seconds/24-hour time/etc. in the other pane.
It's actually very flexible, but not laid out very simply.