The belt system is a fairly new concept to begin with. In the old days they just knew who was senior. The belt testing system to me is just another way for a school to make money. Saying that someone must train for so many years before they test, even if they are ready or capable is outragous. I can see the benefits of a belt system. The incentive it can offer. At the same time I can see the gree behind it to. And people all to often by into it. I Hap Ki Do, since we traditionaly do not have Katas, it is said that if you are a diligent student that practices 2 hours a day 5 days a week minimum, and you are good, then it is possible to attain first dan in 18 months. Now the student should be capable and driven. Anything else and it will take longer. But all to often it is the belt that is focused on and not the bigger picture. And if I have to say what that is then you'll never truly understand to begin with. We test students when they are ready. I am not going to force someone to stay at a certian rank just to get more tuition, and keep them in the school longer. Its all about money to soooo many people. So my answer to this question is. Test them when they are ready. Put the responsability to pass their promotion test, on them.