Kubernetes by default doesn't provide this feature but you can use Another Autoscaler controller for that.
We are using this tool in my company to save some money on the Kubernetes clusters with GPU instances (P2 and G4DN); Developers using these types of instances generally use them during working hours, so we can terminate pods after working hours and our Cluster Autoscaler will scale-down instances that are idle.
Another Autoscaler page: https://github.com/dignajar/another-autoscaler