Generally there is a time called 'summer pruning' July-August when the fruits are enlarged and the branch the fruit is on starts to grow longer. To allow the fruits to develope better, especially on limiting rooted trees. A gardener might prune the extension on a shooting branch back to 3 leaf axils. It can also be done on none fruited branches to control growth ,especially if rainy and few fruit. In about February when tree is still dormant. Have a look at the tree, prune for shape and to curb any overgrowth of a particular part of a tree. There is no convention for pruning at this May/June time of the year.