Once a week, on Fridays, we have found it best for the map and set up to change weakely. This came about for a number of reasions, one people tended to tire of the setups toward the end of the week and numbers were lower as a result. Another pluss from weakely rotations is that we can bring a larger selection of set up's to the CT goers, if you do not like Japanese planes they will only be up a week, and so forth.