Stationary satellites are not truly stationary. They are assigned a "box" of space, a square, so to speak. When they drift to the edge of their assigned space, they are sent slowly back toward the center of the box.sphester wrote:What's the box you refer to?
If you align your dish while the satellite is at one of the box corners, the signal will not be as strong when it gets to the other corner. So you align it when it is at the "center of the box". In the U.S., we used to have a number we called to get the date and time the satellite next will be at the center of the box. It appears to be available online now. Google Satellite Center of Box Calculator and go from there.