To clarify; the movement of the sun simulation is fine. Just our visual description of the compass direction was completely arbitrary and not giving you a relevant direction. Which has been changed on the beta.
I believe the team have already changed the arbitrary direction to be +90 degrees on beta, which may come out as a hotfix.
Above a bit I provided some more explanation, but briefly the old implementation there was no model for compass direction, north was simply what the vector 0,0,1 was in the game.
However you should now find the arbitrary direction is more in line with what would be expected