If you've been living under a blissfully silent rock for the last couple of days, it may have escaped your notice that an annoying bug in iOS means scheduled Do Not Disturb periods don't automatically end. Apple's response was a rather weak KB article that amounts to a shrug and a claim that the problem will "resume normal functionality after January 7, 2013".
Digging into the problem
I did some manual testing by winding my iPhone's clock forward several years and setting different times to turn DND on and off again. You can replicate this easily by scheduling one minute of DND, changing your iPhone's date and time,
