We start dormant pruning our older apples from December 1st on through mid-April. We cut off suckers with excessive growth off. Some limbs are cut off to give ample spacing for good light (need light for good buds) and enable picking at harvest time. Some limbs are tipped to a good bud or weak branch going in the desired direction to contain the tree so it doesn’t invade the equipment travel lanes and depending on the training system being used, will trim to keep a Christmas tree shape in order for the tree to get good light as the sun goes across the sky.
Also, some buds or small limbs are removed to manage the crop load for even bearing crop year after year as only about 5% of the apple flowers are neede