NSDate相差8小时
NSDate *date = [NSDate date];
NSTimeZone *zone = [NSTimeZone systemTimeZone];
NSInteger interval = [zone secondsFromGMTForDate: date];
NSDate *localeDate = [date dateByAddingTimeInterval: interval];
NSLog(@"%@", localeDate);
NSDate *date = [NSDate date];
NSTimeZone *zone = [NSTimeZone systemTimeZone];
NSInteger interval = [zone secondsFromGMTForDate: date];
NSDate *localeDate = [date dateByAddingTimeInterval: interval];
NSLog(@"%@", localeDate);