Phreakish, I have another question if I may, I went back over the calculator's for figuring inv closing point and not one asked for the ICL except the one that you showed. They asked for the advertised duration divided by 2 then add the LSA then subtract the amount of advance of the cam if any then subtract 180 equals the inv closing point. Why don't they ask for the ICL? If I don't have a cam card how can I find out the ICL of a cam? I'm going to use the Wallace calculator. I'm not saying that what you're saying is wrong I simply wanted to say what I read. I thank you very much for your help on this.