Apple’s “Do Not Disturb” caused a bit of frustration for some users on New Year’s Day by not turning off. No word as to why the issue occurred, but Apple posted a note on their forum that says the bug in iOS 6 will fix itself after January 7th.
“Do Not Disturb scheduling feature will resume normal functionality after January 7, 2013. Before this date, you should manually turn the Do Not Disturb feature on or off. To turn off the scheduling feature, tap Settings > Notifications > Do Not Disturb and switch Scheduled to Off.”
The Do Not Disturb feature gives users the ability to silence calls, alerts, and notifications.