CNN - Your iPhone really hates the date January 1, 1970. It hates it so much that it will permanently crash if you change your iPhone's time settings to that date.
It's not totally clear why the crash is happening or why someone tried to set an iPhone's clock back 46 years.
January 1, 1970 is the earliest date you can set your iPhone to. If you turn your date and time settings to manual, please don't do this, and scroll the calendar back as far as you can go you can only go as far back as January 1, 1970.
That's because the phone and other gadgets run on Unix time which has been counting every second since January 1, 1970.
If you turn your clock all the way back and your time zone isn't GMT your phone will think you are in a time before January 1, 1970; which to the phone doesn't exist. Cue your phone turning into a brick.
People have been recreating this phenomenon and posting it online. In those videos the iPhone works immediately after the date is set all the way back, but powering off the phone and then turning it on again will give you an endless greeting screen, with the apple logo just staring back at you for the rest of time.