An iPhone bug will continue to plague users until it fixes itself, manufacturers have said.
The 'do not disturb' mode is designed to silence phones for selected periods but it stopped working on New Year's Day.
Apple has said the glitch will continue until Monday, when it should resolve itself.
"After January 1, do not disturb mode stays on past its scheduled end time," the firm said. "The 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."
The popular function was added to the latest version of Apple's iOS software so people could sleep or attend meetings without disruption.
But it sparked an outcry when users found it did not reset itself as scheduled on New Year's Day.
Many took to Apple's website to express their frustration. One user wrote: "I have to switch it on and off manually, which is of course next to useless".
Another said: "It's really disappointing but it seems that apple has started to reduce its software quality!".
Other users described the issue as "very frustrating" and reported similar problems happening at the same time each year.