I’m no expert, but I remember some advice from some knowledgeable person on Gardenweb (who is probably a member here now) that said, “the best time for pruning is when I’m in the orchard with pruners”. The implication was that he pruned pretty much year round and whenever a tree needed it. I’m guessing that a heavy pruning job right before the tree went dormant isn’t a great idea because the wounds won’t have time to heal, but other than that, do it when it’s convent. That was my take away, anyhow.