Guys in case you forget the reason the Day Night Cycle was difficult for the first game to do wasn't because it was difficult to simulate a sun going over the sky with changing shadows... that was the easy part.
It was giving every single NPC in the game a daily routine and structuring quests around taking advantage of it.
This is doubly difficult in the second game where time is quite variable.
That's pretty much what I said a few posts back: there's the visual effect of day & night cycles and then there's the way it affects characters and what-not: it doesn't necessarily
need to do both. Though having done the latter a fair bit, it's not necessarily that difficult, but it can be a fair bit of work (I guess especially if the game engine doesn't have clock-triggered quests: I have no idea if the D:OS series does or not since I haven't done any mods for it).