Well I worked out how to center it that way on my own, but that isn't what I meant. Using that method, two pinned apps will be right next to each other; when they're truly centered, they would be equal distances from each other and from the taskbar's edges. If you've used the flexible spaces in Firefox's customization menu, you know what I mean.
And I don't need a clock on my desktop, I want to replace the one on my taskbar. By default it's saying "9:29 AM 30/3/2010" in a size 10/12-ish font. I'd like it to just say "0929", "1844" etc in a size 16-18 font, with no date.