This is a perennial discussion item in the testing forum. The answer to your question, obviously, is "yes" -- otherwise they wouldn't do it. In USAF, "a year or so" would actually be testing at a pretty brisk pace after the first couple, and 2nd kyu to 1st kyu is 300 practice days and two seminars per year.
Wow, that's quite some time. Do you train to syllabus as well. I'm not even sure the larger organisations over here train to that extent from 1 grade to the next.
We don't train to any syllabus per sť however we cover everything so it means anyone coming in to the class could be training on Dan grade stuff or we could all be going through basic techniques. It means that some of the lower grades are pretty advanced for their level which has been picked up on during seminars.