 The time of day varies mainly with the longitude of the satellite and receiving station, while the exact days vary mainly with the station's latitude.Stations along the equator will experience solar transit right at the equinoxes, as that is where geostationary satellites are located directly over.Note that with large dishes, it would be possible for the feedhorn to be damaged, which is prevented by the parabolic dishes being done in a flat (non-glossy) finish that does not focus light or heat effectively.