On the '11 M37 with Navigation, there is a setting under Settings>Other>Comfort for "Light Sensitivity. This is for the headlights to turn on/off automatically.
The manual says for higher sensitivity move (pointer) to right. For lower sensitivity move to left.

I want the headlights to come on early (on at dawn) and stay on longer. So do I want the light sensor to be more sensitve or less sensitive?
I tried it both ways but I'm still not sure how this adjustment works.

On my 2007 - the higher the sensitivity, the longer and more often the lights will come on. I backed it off with the HIDs and had it at a higher sensitivity with the halogens.