I just built an Alpha Clock 5 (I only needed a little help from Windell to figure out why some of the display segments weren't lighting up). It's the first clock kit that I've built since a Heathkit, about 40 years ago. Hopefully this one won't require me to periodically re-seat the display modules :-)
I've been looking through its features without trying to read the source code (that's my next step). I see that one of the night light settings is "sleep." The other settings (off, low, med, high) are pretty clear, but what does "sleep" do?