Exactly what I wanted! It glows very faintly in the dark, but lights up when you want it to, and the light level is adjustable.
The clock runs on 1 double A battery, the LED lights require 3 double A batteries. The USB plug can run the lights without the batteries, but I hung the clock high on the wall, so I'm just using batteries.
To activate the LED lights, just cough or clap or say HEY and the entire clock lights up.
I like it- it's exactly what I was looking for AND the bonus LED light-up feature is an upgrade to my expectations.