NSTimeZone localTimeZone vs systemTimeZone

Question

What is the difference between [NSTimeZone localTimeZone] and [NSTimeZone systemTimeZone]?

Answer 1

According to the NSTimeZone reference of iOS, the systemTimeZone represents the timezone used by the system (device) itself.

The localTimeZone returns an object that represents the current default time zone for the application. The application can change its default timezone via the setDefaultTimeZone call.

There are no exposed Cocoa APIs to change the system time zone, or to change another application's time zone.