Iphone Do Not Disturb Not working?

I downloaded the new IOS for my Iphone 4s and set the Do Not Disturb function up to come on at 9 pm and go off at 7:30 am. I see the moon symbol on the screen so it shows the DND is on, and I have set 3 numbers as favorites, but the favorites are still not ringing through. I missed a call the other night from a favorite, didn't ring, didn't light up the screen, nothing.

Am I missing something?

Go into the notifications and go to "Do Not Disturb" from there it will say allow calls from. And click on Favorties. So now you'll only receive calls from your favorites.