iOS 9.3 is coming in the Spring and will introduce Night Shift as well as a number of other new features.
Apple's iPhone Activation Servers Experiencing Extended Outage
According to one tipster who called Apple about the problem, the company's activation servers are currently down. Another AT&T employee has told MacRumors that AT&T has also confirmed the outage, and posts in Apple's discussion forum offer similar information.
Reports of problems began surfacing nearly three hours ago, and there is no word yet on when users can expect the issue to be fully resolved.