When "Day/Night" (BIT1) and "Extended Night" (BIT6) flags are set in ARE 0x48 offset the engine automatically plays movies during day/night transition, even outside cities.
Day / Night movies are meant to be used only in cities (or at least I don't remember them playing elsewhere in vanilla games).
How to reproduce:
1. Optional step to make testing faster: change in-game FPS setting in INI file to 60 (this will make the time run twice as fast) and open BALDUR.GAM file changing current time (offset 0x8) to 1500 (this will set the in game clock to 5 AM at the start of the game)
2. Start a new game with any character
3. - if you are testing it on BG2:EE than teleport to Shadow Temple Land:
- if you are testing it on BG:EE than teleport to Bandits Camp:
In both cases these are vanilla areas with "Day/Night", "Extended Night" and "Forest" flag set by default. "City" flag is not set on them.
4. After few minutes (when the time will be between 6 AM and 7 AM) day/night transition movie will be played.
1. exclude automatic movie playback if "City" flag is not set (not sure if other flags already excludes these movies but "Forest" doesn't)
2. or remove hardcoded movie playback from "Extended Night" flag and replace it with scripted solution (few lines of code added into area scripts - I can provide code for this if needed). This flag is already used to assign night version of MOS file (minimap). We don't really need this additional hardcoded movie functionality there.
3. or unhardcode automatic day/night movie playback into 2da file, for example like this:
AR1400 niteday daynite
The last option would be the most modder friendly solution. It would allow setting area for these movies (column 1) and specifying movie names that should play during transition (column 2 and 3).
What do you think about it @Avenger_teambg