BA do 10 flights a week LHR-CPT-LHR for part of the northern winter, the daily flight is a night flight both ways and the 3 extra flights are turned around and do a daylight flight back to LHR. It does seem inefficient to have 3 747's (1 in CPT and 2 in JNB) spending the day on the ground in SA but the pax like night flights! Virgin have only done daylight flights north bound out of CPT I believe.