iOS 9.3 is coming in the Spring and will introduce Night Shift as well as a number of other new features.
Apple Cites 'Incredible' Demand for New iPhones Amid iPhone 5s Sellouts
“Demand for the new iPhones has been incredible and we are currently sold out or have limited supply of certain iPhone 5s models in some stores,” an Apple representative told AllThingsD.
Shipping estimates for online orders of the iPhone 5s opened at 7-10 business days in many countries, and while the device launched with 1-3 business day shipping in the United States, estimates quickly slipped to a minimum of 7-10 business days and even "October" in the case of the gold models.
In-store stock has also been very tight, with third-party retailers and even some Apple retail stores having little or no stock of gold and silver iPhone 5s models. In-store stocks of iPhone 5c models appear to be much more plentiful amid lower demand driven by excitement for Apple's higher-end iPhone 5s with early adopters and the availability of pre-orders for the iPhone 5c.