This feature will likely be introduced to the big public in Spring 2017 with the introduction of the Windows 10 Creators Update. Third-party tools with this sort of functionality have been around for many years, the idea behind it is that exposure to blue light before bedtime negatively affects your sleep pattern.
The Blue Light setting will also be accessible via the Action Center.
Furthermore, there's also speculation going around that Microsoft is working on a Game Mode:
.@h0x0d looks like Windows will adjust its resource allocation logic (for CPU/Gfx etc.) to prioritize the "Game" when running in "Game Mode"
— WalkingCat (@h0x0d) December 28, 2016