The interesting thing here. At least as far as ASU goes. 1 training day= 1 hour no matter how many days of training you actually had that day it still only counts as 1 hour. I could go to a seminar and d 4 hours and still it is 1 hour. I can go to class 3 days a week train 2 hours each day and be credited the same training time as the fellow who comes to class 3 days a week and only trains 1 hour. And by that rule, were that person and I to train for the specified number of hours we would both be eligible to advance at the same time in spite of the fact that I in reality put in twice as much effort.
None of it really matters though if the teachers are not just abiding by the time period/hours trained and are not allowing a student to test until he reaches the appropriate skill level to merit advancement. And that is a bit harder to weigh and measure I think.
The training day=1 training hour is a way to keep track of official "hours" - however if someone actually spent 6 hours doing rigorous training for every official hour recorded, they'd be a much more robust shodan (or nidan, or whatever) than a member of the same or another dojo, who only put in the actual one hour per session.
As some may recall I coach rowing. One fellow I coach puts in 90 minutes/day sculling (he's 16) as well as 2 weights sessions/week plus usually 3 other non-rowing workouts per week. He's not going to go as fast as the national team guy who, at age 24, is training 3 times/day for between 60 and 90 minutes per session, 6 days/week. The 24 year old who's only training as much as the kid I coach will probably go faster than the 16 year old because of physical maturity, but not as fast as the national team type. (the 16 year-old I coach would do more training but he's not allowed on the water unless a power-boat is on the water for safety cover, and I work at two different rowing clubs, so I'm only available for 1/2 training, and he can't go on the water more often)
Similarly, a shodan candidate who trains an hour a day 6 days a week may be able to do all the techniques called for and survive whatever randori/jiu-waza requirements are part of a shodan "test", but the shodan candidate with 6 hours/day 6 days a week (36 actual training hours/week) is going to be much less stressed by the test and should have a much easier time of it. (and would probably make mincemeat of the one-hour/day person) They'll both have the same number of official hours - which suggests that the ASU system needs some review...