Thinking from the perspective of a modder... If we can make maps, we can make maps dark. If we can create scripts, we can force a certain time or event to trigger 'night,' aka a duplicate map of the original in dark form. This would be more akin to games where it's always day until you 'sleep.' It's not a realistic solution, but modders could certainly create this version.
I prefer the approach of the "weather" (including day/night cycles) as well as NPCs, creatures and so on just following a clock: I'd rather not see a sudden transition or two maps that could get out of sync.
My main experience of modding was with Oblivion, but a simple clock that dictated the weather as well as triggering schedules seemed to work very well. From an RP perspective I preferred to have my PC questing during daylight and catching up with some much-needed sleep at night; and where nights were concerned I added a mod that made them typically dark enough (dependent on weather and the location of the moons) where I couldn't see my hand in front of me, and decided I'd be better off in a comfortable bed (or even a straw mattress with fleas!) than using a torch and various spells to combat the darkness.
