Seems like there is a SW issue with 64bit iPhones on dealing with time if you set the date/time to Jan. 1, 1970/00:00:00. iOS is using Unix time to track time. This means that the time on your iPhone is defined as the number of seconds passed from Unix Epoch (January 1st, 1970 at UTC) until now. This number is then converted to your local date/time based on your time zone or any other setting you might have.
Setting the time to Unix Epoch (January 1st, 1970 at UTC) seems to be a bad idea and various trusted sources confirmed this rumor. If you really what to try this keep in mind you have a big chance to transform your iPhone in a very expensive aluminum brick :) You brick will only show the apple logo and will fail to boot into your iOS entering a strange restart loop. If you or any of your friends made a prank on you and made you crash your iPhone you have 2 solutions to make it work again:
- First solution is to reset your device doing a classic unplug of the power supply (battery). This solutions seems to be the one that is most recommended because you are still able to get back your personal data but unfortunately requires a little bit of service work while the battery is not easily removable. Therefore, the best is to ask for help in your local Apple Store or service. Of course, you can do it at home using a small screwdriver to lift the display and a soft plastic tool to remove the battery connector. Check out this video:
- Second solution is to make a hard reset while connected it to iTunes. Press both Home button and Sleep/Wake button and keep them both pressed for around 10 seconds. At reset you might be able to start a device recovery. This solution might be better if you don’t want to unscrew your device and mess up with his internal components but you might not be able to restore your personal files.