I have been putting in about five or more hours a week. I am just curious as to the minimums. Are they written in stone for organizations such as the USAF or are they flexable to the abilities of the student. If a student is ready to test then I am sure the instructor will let me know, but what if I need 100 training days, but am ready at 60? Can the sensei bypass those required days to allow the student to test?
In the USAF they are pretty much in stone. There are minimal for kyu ranks within the USAF, both in ability and in hours. Your individual Sensei who would be either a fukishidoin or shidoin might
advance you through the kyu ranks at their digression, irregardless of hours if they think you are of a certain ability. I'm not at liberty to judge whether allowing students to have an exhilarated advancement through the kyu ranks is a respectable action by a Sensei or not. All I know is that some sensei think it is okay, other's think it isn't okay!
(If you sensei is a shihan, you are at luck to not have to worry about traveling to a shihan to test black belt.)
Now as for Black Belt. There are standards, and if you aren't up to the standards in both hours and ability, I wouldn't bet on a black belt within the USAF. USAF also requires you to attend two seminars a year. Basically, go out and see the Shihans! lol
If your ability or days are not up to snub, you won't pass. (Typically when your hours aren't up, your ability isn't up either, generally! There are exceptions.)
And I don't know if you have been keeping up with Yamada Sensei's new letter or not; but I was at Winter Camp last year and Yamada Sensei held the black belt tests. There were a few people testing who didn't have their hours, and didn't have their basic skills in order for a Dan testing. Those people flat out failed. And their Sensei reportedly had a good talking to! Which was followed by a less than happy newsletter by Yamada Sensei, reporting his concerns. (Yamada Sensei's writings are on Aikido online)
Basically he was pissed off.
It is always best for your career within any organization to not piss off the chairman of that organization
So basically what I'm saying is that there are no exceptions, other than physical limitation, to the minimal standards of the dan testings.