Manually setting the date of your iPhone or iPad to 1 January 1970, or tricking your friends into doing it, will cause it to get permanently stuck while trying to boot back up if it’s switched off.
When the phone is turned off and turned on again, it refuses to reboot, simply displaying the Apple home screen and going no further.Users have reported that the only way to have the phone fixed is to take it into an Apple Store.
Check out this video by a YouTuber.
— QS2 Point (@QS2Point) February 12, 2016
The precise cause of the issue has not been confirmed, although speculation points to the way iOS stores date and time formats meaning that 1 January 1970 is stored as a value of zero or less than zero, causing every other process that requires the time stamp to fail.
Jailbroken iPhone users can protect themselves by using several tweaks that prevent the date being set to 1970. Other users can protect themselves by not turning their iPhones off, manually setting the time and date and turning off automatic time changes.
Apple company said that it was looking into the bug.