Most keets moult in the spring. They also will do some moulting throughout the year - obviously they can't replace ALL their feathers at one time or they'd be bald and unable to fly.
How much they moult at one time, and how often they moult, varies from keet to keet.
My two are almost always growing in a few new feathers. Every few months they'll grow a bunch at once, but not in the HUGE moults like some keets have.
In other words:
Your keets will moult again before next spring, but nobody can really tell you when, how often, or how major. (The good news is, they don't get as cranky when it's just a few feathers involved.)