update : Apple replied that the bug will be fixed itself on 7th Jan, so stay tuned.
People who are using Do No Disturb feature in iOS 6 most probably now have noticed that this new feature from Apple is not functioning well since the first day of 2013.
It's the latest bug from Apple, after the wifi bugs since the iOS was realized.
The bug makes the schedule of DND not working well. It does not switch on and off according to your set time in the schedule.
Now users have to switch it on or off manual.
Google it, and you will find a huge amount of similar complaints from the iOS user all around the world.
Seem like crossing over into a new year is big deal to Apple. ;P