The Parades Commission used to have an RSS feed of upcoming parades, but that functionality was lost in a site redesign in 2014.
What I'd love is the ability to run their Advanced Search to specify, say, a town and a date, and find out if there are any parades that day. (Their current Advanced Search doesn't seem to work that way - when I try, it doesn't seem to restrict it to the town, just the date.) That would be awesome.
Alternatively, an RSS/XML feed like they originally had would allow me to download and query the data myself. Even having that would be great.
One important note (and I know I've ranted about this before) - having the data program-accessible is important. Tagging a parade with an actual location and date/time would be great - it's hard for a program to differentiate between a parade in Antrim and a parade on the Antrim Road in Belfast, and hard to accurately interpret dates and times if they're just in a freeform text field.