Hours on the mat?
You know ... depending you where you are in the span of years of your life, how far along you are in your training, and what you want out of your training, can drastically change the hours you train?
For instance, Say you do three classes, at an hour of mat time with a half hour of stretching three times a week, that could be interpreted as either three hours, or four and a half hours. Say you go to a seminar that has two hours of mat time scheduled, but the sensei lets the session run over for the morning and afternoon, you could average another three and a half hours for that particular week?
Or, if you are teaching? Two, maybe three classes a day, four or six days a week, averaging three to four hours a day ... that could easily be interpreted as twenty plus hours a week?
How many actual hours of practice for one week, do you actually learn, or benefit in the arena of proficiency in acquiring more acute skills in Aikido?
I would say when I could do four or five classes a week, the average classe with advancing skill was about two hours each week for mat time, and one hour a week with out of class practice, study, and reading.
Whittle down the time, observe the insight, and find your own balance of learning, maintainence for the distance you have come in learning? As you understand the connection of movement and techniques, how much harder is it to go further, and further?
Maybe that is why the old guys/gals smile when the new guys/girls come to class? We wish we could start over with such wonder, energy, and once again cover old ground with new eyes ... once again.
How many hours?
So long as they are fruitfull and fill with wonder, does it really matter?