60 minutes for a number of reasons. First, it takes me a while so a shorter timeframe is pretty much guaranteed to be insufficient most of the time. Second, my budget currently allows me about 30 hours per year so longer sessions require a greater gap between sessions. third, as like to find & visit one regular SP, I do like to be a regular regular & not one that sees her irregularly. And fourth, if I cannot get it done in an hour, it probably isn't going to happen that session.