I've asked you how long it takes to attain the rank of black belt (here).
Now I'm interested in how long it takes to achieve 2nd Degree Black Belt (for arts that have this rank). This question assumes, of course, that the 1st degree black belt in question is actively studying the art (as opposed to people who attain 1st degree black and then disappear).
Some arts typically use a rule of thumb of each degree rank of black takes the number of years of the rank (that is, two years for second degree, three for third degree, and so on).
Others follow no set pattern like this.
I'm interested in how your art, organization, or school handles this question.
How Long to Second Degree Black Belt?