NSDate and the
timeIntervalSince* methods will return a
NSTimeInterval which is a double with sub-millisecond accuracy.
NSTimeInterval is in seconds, but it uses the double to give you greater precision.
In order to calculate millisecond time accuracy, you can do:
// Get a current time for where you want to start measuring from NSDate *date = [NSDate date]; // do work... // Find elapsed time and convert to milliseconds // Use (-) modifier to conversion since receiver is earlier than now double timePassed_ms = [date timeIntervalSinceNow] * -1000.0;
There are many other ways to calculate this interval using
NSDate, and I would recommend looking at the class documentation for
NSDate which is found in NSDate Class Reference.