iOS 9.3 is coming in the Spring and will introduce Night Shift as well as a number of other new features.
WWDC 2011 Sells Out in Under 12 Hours
Less than 12 hours after passes went on sale, Apple's Worldwide Developers Conference set for June 6th-10th has already sold out.
Last year's edition sold out in eight days, and brisk sales were expected again this year, but a complete sellout within a matter of hours may still have taken some developers planning on attending by surprise. This year marks the fourth straight year that WWDC has sold out.