For All United States Kendo Federation (AUSKF) you need to wait 6 months between ikkyu and shodan. It is difficult to do it in this timeframe unless you travel for kendo a lot.
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Nov 18, 2008 Rating
Ranking system in Indonesia by: Anonymous
In my country, Indonesia, we have a kyu exam three times a year. It is usually held in 3 different cities. In that 3 times, we can take the exam as many as we can. But, for the dan exam, we only have one exam a year.