My concentration at that point was miles below Wallace's standards, and yet somehow it was more than sufficient for what I was looking for. Thus, I think that, while it is always fun to have a high bar just to see if one can do it, one must ask what is the value of that bar if the core goal can be achieved on far less. I can attain to Nirodha Samapatti but have never yet sat in a jhana for 24 hours. There is a flaw in his model regards timing.
Daniel,
Of that fact, "there is a flaw in his model regards timing," there is no doubt. But he is a Samatha Yanika, in affect. So that stands to reason, he would form that opinion. But it was my impression from the book, that about 8hrs, was what was required as that access to Jhana, as there were some student that were still in access concentration but where meditating for 7 ½ hrs.
Working within these understands of Jhana, based on the commentaries. The question that arises for me is what is access concentration, what level of concentration is high equanimity. And if I've been told, that high equanimity can be around four hours of sitting with pliancy (Obviously I realise, though it is also worth saying, that this could in affect be reached in one or two hours, as the time is not a measure of the actual refinement of the state.) by teachers, after I've told them, I'm sitting for 2 and a half or there abouts (meaning sitting 1hr, then 2 1/2hrs or 1hr then 2hrs and then another 1hr, with a brief leg swap at those intervals. Sits something like that, and with high levels of pliancy after the first hour).
So really, I'm just trying to define access concentration in relation to that advice. Access Concentration or neighbourhood concentration, being a step that is required, before the attainment of path. Path which is considered, in the commentaries to be the equivalent of jhana or in a state of jhana at the point of realisation.
Sorry, if this doesn't come across as a question, or if it appears to be telling you things you already know. I've mentioned all that long winded stuff as its tied into my confusion. Or my desire for confirmation of this pattern of understanding.
Lastly thanks for your Dharmic contributions Daniel and also thanks to Hokai for his comments on this thread.