Train an Animal
You can use the Handle Animal skill to train an animal. The rules for training assume the training period is continuous. However, you can break this training into smaller increments (allowing you to make progress on this training between adventures), but you must attempt a Handle Animal check for each training period, and the DC increases by 2. Failing the check means that training period doesn’t count toward completing the training.
This use of downtime doesn’t allow you to exceed the animal’s normal training limitations. For example, spending downtime doesn’t allow you to teach an animal more tricks than it could learn if you weren’t using the downtime system.