I've done some quick searching and I'm finding mostly non helpful answers like "when you have the time" or "when the weather is cooler". I know there is a "best" time, based on moisture percentage. 90% of the wood I have available is oak, so I'd like to cut the trees when most of the moisture is out of the tree. What time of year does the sap and/or moisture go back to to roots? When does it start coming back? I'm not an arborist so I'm probably not describing it properly. What is the science behind this? An oak cut down in February has a lot less moisture in it than one cut down in August. With the long seasoning times of oak I'd like to make it count. Thanks!