As we know
in mid- febuary, the January 1, 1970 bug was discovered that caused all 64-bit
devices like iPhones and iPads to be disabled or “bricked”(stuck in
the Apple logo) when the date was set to January 1, 1970. 

As we know in mid- febuary, the January 1, 1970 bug was discovered that caused all 64-bit devices like iPhones and iPads to be disabled or "bricked"(stuck in the Apple logo) when the date was set to January 1, 1970

But with the release
of iOS 9.3 beta 4 provided to developers and public beta testers earlier this
week, Apple has fixed the issue caused by the bug January 1, 1970. In addition
to that, iOS 9.3 also includes several new features such as Night Shift mode, password
protection for the Notes app, new 3D Touch actions for stock apps
like Weather, Settings, Compass, enhancements to the
Health and Activity apps, iCloud for iBooks PDF syncing, App Store, iTunes
Store and much more.

With iOS 9.3beta 4 software update, the date can’t be set beyond December 31, 2000 at 7:00
p.m. ET that effectively ends to the January 1 1970 bug. This is the great news
and by now no one can use this trick to brick someone’s device and you don’t
need to remove your battery or attempt risky self-repairs.
The iOS 9.3
beta 4 software update is currently only available to developers and public
beta testers and final version of iOS 9.3 will be available widely in the
spring and is expected to launch iPhone 5se, the iPad Air 3, and new Apple
Watch bands as said by Apple.
If you are jailbroken, you don’t need to upgrade to latest version to get
rid of this bug. Simply try this fix on How to protect your iPhone from the “January 1, 1970” bug

Source: Macrumors