It depends a lot on what you are pruning. Dead, diseased or damaged wood can be removed whenever it is discovered. Aesthetic pruning or shaping for form (includes niwaki) is best done as the tree emerges from dormancy but before active growth. Candling is done when the candles are present but not yet fully developed.

It would be simpler to know when not to prune :-) Summer and fall is when it should be avoided.

Thanks! This is definitely aesthetic.

At beginning of Nov I cut off a small dead-from-shading branch on my southwestern white pine and wondered if there would be any "response". Sure enough, couple weeks later and the little wound on the trunk was covered in sap. Kinda surprising given the cold temps.

I've used this from Virginia tech, for general use. Not that I have anything exotic. :-)

https://vtechworks.lib.vt.edu/server/api/core/bitstreams/9c3fad6b-71cf-4612-b7ef-ad0bd30b8aad/content