It's been my experience that sunlight doesn't move (change angle) or fade (going from day to night). I've set up experiments with the sunlight settings and found that they are constant regardless of time of day. The angle seems to be preset as well. Which wall gets the extra light depends on which way the static is placed in the CS. There is a default north in interior cells, and setting the northmarker doesn't effect the cells direction for the lighting. We had this same discussion at TR a few months ago. If I can dig up my test cell I'll post it here so all of you can check it out.
KF
Edit: Here is a little test .esp to help everyone understand how lighting works.
It's a series of cells with different light settings. If you have any more questions, feel free to ask. I'm not an "expert", but I have done my homework.
It's just a few cells with a single room for each extreme of the settings. The cell names tell you which settings are in effect for the cell you're in. Load the esp like any normal mod, go to Seyda Neen, and there will be a door in the middle of the courtyard just beyond where you exit the excise office. If you open the inventory, you can see the cell name on the top of the map window. Hope this helps.
