How can I locally detect iPhone clock advancement by a user between app runs?
CACurrentMediaTime & mach_absolute_time Take a look at this questions: iOS: How to measure passed time, independent of clock and time zone changes? Calculating number of seconds between two points in time, in Cocoa, even when system clock has changed mid-way CACurrentMediaTime uses mach_absolute_time: http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/CoreAnimation_functions/Reference/reference.html Here you have an example on how to use CACurrentMediaTime: http://www.informit.com/blogs/blog.aspx?b=02b4e309-308c-468a-bab1-cebb1404be6a … Read more