This sounded like a good idea to me when I came across it (I think on HN?) a while ago. The logic makes great sense.
However, what I found was that when I come home late at night and want to work on something, I'm planning to stay up a while. I don't want my screen to go low-contrast and dim, I want to stay up and work! When I'm working late, I expect my computer to stay up with me. It felt like my computer was getting sleepy before I did. Eventually, I removed it.
We have a UI in the works for "night owls"...people love the sunset, so we'll still include it, but we'll have a longer transition for people who want to work late (or who live in northern climates).
However, what I found was that when I come home late at night and want to work on something, I'm planning to stay up a while. I don't want my screen to go low-contrast and dim, I want to stay up and work! When I'm working late, I expect my computer to stay up with me. It felt like my computer was getting sleepy before I did. Eventually, I removed it.
Neat idea, just didn't fit my use case.