1 Just some brainstorming:
4 + Add multiple "pages" like wmMoonClock?
8 + Twilight Calcs. Civil, Astro, Nautical....
12 + Graphical Annalemma or plot of Eq of Time...
14 + Add user definable twiddle factor to account for local
15 terrain etc.. Could even go way overbaord and download
16 USGS topo info? (Man! that is going overboard!).