OsSetRegionSunSettings

Function Syntax: osSetRegionSunSettings(bool useEstateSun, bool sunFixed, double sunHour);
Returns: NULL

Example: 

default
{
   state_entry( )
   {
           osSetRegionSunSettings( FALSE, TRUE, 12.0 );
               //Sets the region/ terrain-tab to non-estate, fixed-sun and at dusk settings.
   }
}