I was just recently thinking during map making that I'd love a way to change daytime/nighttime, since there are certain mobs that only work during nighttime. this is not very fleshed out though, I'm assuming you want to have part of the map behave like it's night?
so I go straight to wiring and think about how that might improve my mapmaking, for example a 3x3 statue shaped like a clock or sundial or something similar. let's just say if you wire up the 3 o'clock position and trigger it, the game forwards to the next possible 3 o'clock, either 3 am or pm.
AND if you wire up the center and trigger it it changes to night or day, whichever is the opposite of the current.
now that I think about it you could really have some cool stuff like have maps where the days are really short or vice versa or the longer you play a map the shorter the days get and so on, maaan I'm really starting to like that statue idea